Celestial is much calmer and tamer than her brother Gabriel, she would often times attempt to keep him in line soon after they had left heaven before finally giving up. After this she traveled on her own for a while, taking on the persona of Athena the same way that her brother had with the Norse god Loki. During this time she was often looked to for war council and advice from gods of other Parthenons on how to deal with the rising number of hunters, eventually this ended up with most of the hunter's being whipped out a few millennium they have regained numbers, but that aren't as well known or as numerous as they would be.
At one point around 700AD she met and fell in love with a man, he went by the name of Briant and she told him who she was after he asked for her hand; she stayed with him for a long while. He lived a longer life span than most humans of that time would have, though he refused let let her make him live forever because of the attention it would draw to her. She pleaded with him not not leave her alone, to not leave their children alone. Unfortunately he died before she could convince him, and she sent his soul on a path of endless rebirth like he had asked. He did not want to end up in heaven and risk letting the angels there know her whereabouts or of the existence of their children two children Dina and Zuriel.
She met him one time after that, merely a year before she was born as Rebekah Mikaelson. He had come close to death, and that brush with it had caused him to remember her and he had called for her–prayed for her. When she came however it was to late, and though she was able to speak to his spirit before it was reborn she was unable to save him. When she sent him on this rebirth she had made it impossible for anyone except for maybe God or Death himself to be able to stop the continuation of the cycle, otherwise it was possible that they may try to stop it and get answers about how he kept being reborn.
After that she talked to her children, she told them that she was growing HEAVY and SAD and that she was going to pull out her grace to live as a human without her memories for a while. Though Dina and Zuriel were not entirely happy they wouldn't be able to see their mother for a while? They told her not to worry, and that they would take her grace and make sure it stayed safe until she made it to the end of her human life. Though she never managed to do that.
After that she was born as Rebekah, the 6th child of Esther and Mikael, as well as the only living as far as any but her Mother and Finn knew at the time daughter of the family. She was very much doted on by her elder brother Niklaus, and tended to follow either him, Elijah or Kol around a lot of the time when they were younger. When her brother Henrik was born she was ECSTATIC about being an older sibling, and was bent on being a wonderful elder sister just as her brother's as been great to her. And she was, she dotted on him and treated him well. She always made sure that he had what he needed, and once or twice even stood between when their Father tried to punish him well in one of his worse moods-she did not want Henrik to be punished because Mikael simply had a short fuse that day.
And then one day everything changed, Nik and Henrik had sneaked out to see the wolves despite the danger it would cause. 'Henrik insisted, he wanted to see them. He just wanted to see.' was what he was mumbling as their Mother rushed away with their younger brothers limp body. Rebekah cried as she held onto Nik, she didn't want to leave him alone when he was so clearly devastated; but she also needed to let out her own grief.
Then? Then their parents turned them, Esther used the spell needed to turn them into vampires at Mikael's insistence. Losing another child had been to much for him, he told her that this was not a grief he was made to experience and that if she loved him she would prevent them from ever losing another child. And that's how things really got started, after the change Rebekah traveled with all of her siblings for a long while. Eventually though Kol separated from them sometime after they left the home of Tristan and Aurora.
Then they met the 5 hunters, she agreed to get information when Nik became paranoid about them. She didn't expect to feel so drawn to Alexander though, little did she knew that they had met before; in another life-under better circumstance they had met ad fallen in love and been happy. Neither of them knew though, not until he daggered her. Not until she was put into such a deep state of almost death like unconsciousness to the point where her mind and body thought it was dying with no help from a spell to bring it back, and so her memories unlocked. The memories of her life as an angel, of all that she had been through and of the fact that she had chosen to be reborn as a human to be happy. The memories that made her realize that ALEXANDER was BRIANT, that that was why she had felt such a pull and connection to him.
It didn't matter though, because he was now dead and all she could do was stare blankly as Niklaus yelled at her and pull into herself with her sob's when he grabbed her; until the undaggered Elijah came in and told him to stop. From then on she kept the secret of everything that she had remembered, though once in a while she would call for Gabriel or cross path's with her children; she never once told Niklaus the real reason that she found a need to speak with them r wander away from his eyes with them. She would just claim that she wanted to have bite in private.