Yes, there is a holiday for each of the Seven. I have not elaborated on those much, but for Maiden's Day, which figured in Cersei's plot against Margaery. (GRRM on Not A Blog)
Demure in white, the little queen would lead her hens to Baelor's Sept to light tall white candles at the Maiden's feet and hang parchment garlands about her holy neck. A few of her hens, at least. On Maiden's Day widows, mothers, and whores alike were barred from the septs, along with men, lest they profane the sacred songs of innocence. (A Feast for Crows)
Have you ever observed that when a man gets a son he takes all the credit, and when he gets a daughter he blames his wife? And if they do not breed at all, we say it is because her womb is barren. We do not say it is because his seed is bad. (Wolf Hall, Hilary Mantel)
261 AC
The candles felt heavy in Cassana's hands. Tall white candles, not unlike the ones she had carried into the sept on numerous Maiden's Day since the coming of her moonblood. But this time she would be carrying the candles on Mother's Day, not Maiden's Day, and she would be walking into the sept not as the maiden daughter of Lord Estermont, but as the lady wife of Lord Baratheon, as the Lady of Storm's End.
"My hands will shake. They will see how nervous I am," she worried.
Steffon's hand grasped hers. "You will do fine," he said, gently.
"And they will know that I am not yet with child." She would not be walking into the sept on Mother's Day during the first stage of the ceremony, the one reserved for wives and widows already blessed with children, or already with children in their wombs. Her place in the procession was not with the women who were already mothers or would-be mothers, but with the other childless wives praying to the Mother to bless their marriages with children. Many eyes would be watching, watching and waiting to see if the new Lady of Storm's End would be entering the sept on Mother's Day with the first group of women, or with the second.
"We have only been married for a few moon's turn," Steffon said. "There is no hurry, no hurry at all," he tried to reassure her.
Oh, but there is, dear husband, Cassana disagreed. There was a hurry, in the eyes of the world. And she would be the one they blamed. Her womb is too barren to nurture life, people would say, of a childless couple. They would not say, his seeds are deficient, unlikely to bring forth life.
No wonder childless wives, not childless husbands, were the ones exhorted to pray to the Mother Above for the gift of fertility on Mother's Day.
The young Lord of Storm's End married for love, they would say, and look how little joy he has had from that, with no heir in sight.
I have made him happy, and he has made me happy, and if no child is ever born of our union, we would still be happy, Cassana revolted. Though, her father's words also rang still in her ears. Do your duty, Cassana. Give him a son and heir. That is the only thing he needs from you.
He needs more than only that, and I mean to give him more than only that, Father, as I would demand more than only that from my husband.
"I would walk with you into the sept if I could," Steffon said, as Cassana's silence lengthened.
"How could you? Men and maidens are barred from the sept on Mother's Day."
"I could disguise myself as a woman."
Cassana smiled. "You would make a very unconvincing woman," she said, stroking her husband's beard.
Steffon pretended to pout. "Would I, truly? I was an astoundingly beautiful child, I was told, one often mistaken for a girl."
"Then you have completely failed to live up to your childhood promise. Are you not ashamed of yourself, my lord?" she teased him.
"Ah, but I have lived up to the promise of the man of your dream, and that is so much better."
Cassana laughed. "You flatter yourself too much, Steffon." Then, solemnly and seriously, she said, "I did not wish to marry you because you were the man of my dream."
Perplexed, disconcerted, looking slightly hurt, Steffon remarked, "No?"
"I married you because I wanted you to be the man of my life," she said. "The only man in my life."
"I dreamed of you, every day that we were apart," he said, "but the dream is as nothing compared to the real thing."
"And now you are trying to flatter me," she pointed out.
"Is it working?" he asked, as his hand started caressing her cheek, then her neck.
She kissed him, long and hard, in reply.
Later, when her moonblood was late in coming and Maester Cressen happily pronounced that she was with child, Cassana would count back the days to estimate the approximate day of conception, and she would determine it to be on or around that Mother's Day. Her husband would gratefully attribute it to the efficacy of prayers and the generousness and mercy of the Mother Above, but Cassana was more inclined to credit the vigorousness and frequency of their lovemaking on that particular day.
262 AC
Gentle Mother, font of mercy, save our sons from war, we pray ...
Save our son from the scheme and machination of this new king, Cassana prayed, silently, as she was singing the Mother's Hymn out loud.
Gentle Mother, strength of women ...
Grant me strength to help my husband see that his cousin is no longer the boy he once knew and loved, the one he would have trusted with his own life.
A man who could be that cruel, that unfeeling, towards his own wife, towards his only sister, was not a man that could be trusted with their son, Cassana was certain. Her tenure as one of Princess, now Queen, Rhaella's ladies-in-waiting had not been a long one, for her betrothal to Steffon had only lasted less than half a year before they were wed. But even in that short time, she had seen and heard enough to be wary of Aerys.
After the hymn was sung, the candles were lit and the garlands duly placed around the Mother's neck, conversation in the sept revolved around the Lord of Storm's End son and heir, the babe Robert.
"And when will you and Lord Baratheon be taking your son to court, to be presented to the king?" asked one lady.
"He will be a royal page and a royal squire like his lord father had been, I am sure," pronounced another lady. "How good it is, to be the king's own kith and kin," she purred. "A place in court is already assured for young master Robert. Others would not be so lucky."
I would call it luckless rather than lucky to serve a man such as Aerys, Cassana thought, but did not say, mindful of her duty as the Lady of Storm's End to be seen to be honoring the king on all occasions.
Steffon was waiting for her in their bedchamber when she returned from the sept. Robert was in his arms, sleeping soundly.
"Your first Mother's Day as a mother. How was it?" Steffon asked.
"It was ... different," she replied, gently kissing her son's forehead. "And yet the same," she continued. The yearning, the anxiety and the desperation were not very different, whether you were praying for a child who has not yet existed, or praying for the safety and happiness of a child already existing.
"We have a gift for you," Steffon announced, with a flourish.
"We?"
"Robert and I."
The ring fitted her finger perfectly. The gemstone was the color of her eyes, her shimmering green eyes. The letters CS were inscribed on the center of the gold band, with an R inscribed slightly further to the left.
To stem the tide of her tears, Cassana said, laughing, "It is hardly a gift from Robert."
"Well," Steffon said, looking sheepish, " you will have to wait until he is slightly older to receive a real gift from him. From our son."
268 AC
Stannis was playing with her ring again. He loved twirling the ring around his thumb, and tracing the inscribed letters on the gold band with his little finger.
"This S is for me, for Stannis?" he asked, pointing to the S next to the C.
"No, that is for your father. For Steffon. This S," Cassana said, pointing to the one on the right of the first S, "this one is for Stannis."
"And R is for Robert," Stannis mumbled to himself. He was not yet five, but already he knew his letters and his numbers better than his older brother.
"Where is your brother?" Cassana asked.
Eyes still intently examining his mother's ring, Stannis replied, "He is getting the surprise, with Father."
"What surprise?"
Stannis looked up, finally realizing what he had said. He gasped, putting his hand over his mouth.
Tickling his stomach and the sole of his feet, Cassana asked again, "What surprise were you talking about?"
He giggled, while trying to get away from her, saying, "No, no, it was supposed to be a surprise."
"Is it my surprise gift for Mother's Day?"
Finally, Stannis nodded. "But I was not supposed to tell. It was a secret, Father said."
Putting a finger on her lips, Cassana said, "I will not tell him you told."
"But Mother, you cannot lie!" her son protested. "You said lying is -"
His protest was cut short by the sight of his father and his brother entering the room. Robert was carrying the gift reverently, as if it was the crown jewel.
It was a book, Cassana saw. And what a book it was! The drawings were all made by her sons' childish hands. Here was Stannis riding a stag, though he had given the stag wings, "so we could fly as well as run," he declared solemnly.
And here was Robert on his pony, though he had drawn himself having a scraggly beard that was meant to look "fierce and frightful," as he put it.
Here was Cassana, sitting on a throne made of turtle shell, holding out both her hands as if beckoning to some unseen figures.
"You are calling for us," Stannis said. "We are your knight err ... err ..." he paused, looking at his father for help. Steffon mouthed the correct word. "Errant," Stannis repeated. "We are your knight errant, Mother."
"But why are you not in the picture?" Cassana asked.
"We made the throne too big," Stannis said, sheepishly.
"There was not enough space to put us there," Robert continued for his brother.
The writing under the pictures was recognizably done by Steffon's own hand, so very familiar to her from his letters. The words were probably a mixture of her sons' and her husband's, the tone lurching from dry and sober recitation of facts resembling an Archmaester's historical tome to breathless, exhilarated and disjointed storytelling.
What a precious, precious gift. She had no suspicion at all that her boys had been working on this. How had they managed to keep it a secret from her?
"Do you like it, Mother?" Robert was the one who asked the question, but Stannis was the one looking apprehensive, in case the answer might be 'no.'
"I love it!" Cassana exclaimed, gathering both boys into her embrace, while her eyes caught her husband's gaze. He looked as giddy and as excited as their boys. Thank you, she mouthed the words silently. He nodded, making his way towards his wife and his sons, joining them in the family embrace.
Later, when the boys had been put to bed, Steffon turned to Cassana and said, ruefully, "I have not give you my gift."
"The book -"
"The book is really from our boys. Tell me, Cassana, what would you like for this Mother's Day?"
"I only want one thing," she replied. She knew exactly what she wanted, what she needed. In a fortnight, Steffon would be taking Robert and Stannis to court for the first time. "When you take our sons to court," Cassana said, "promise me that you will not promise them to Aerys as his wards or his pages. Promise me that our sons will not have to serve this king until they are grown men capable of protecting and defending themselves."