Some spoilers:
. Melissa Carter is daughter of the goddess Selena and the demigod Harry Carter (Son of Maleficent and Hades).
. Before the final battle that took Selena, Nico, Will and Harry's lifes, Selena left her daughter at Clarisse's house with a letter sent to Clarisse. She let Percy and Clarisse adopt her daughter and take care of her as if they were her parents.
. Clarisse goes to Percy's house and tells him everything. Together, they adopt the baby. After months, they became such goods friends, for years later to get married.
. Annabeth was killed by Selena's evil clone. Percy had almost destroyed the world for her, by joining Kronos in the final battle before Selena's death. Clarisse was the one to put some sense into him. She lost Chris in the battle. Both of them conforted each other and regretted their mistakes and tried to move on with their lives.
. Eris turns into the new queen of Tartarus. With Kronos help, before he died and disappeared completely, she was able to connect all the gods' lifes to hers. If she dies, they all die.
. Selena grows up without her real parents and thinks Percy and Clarisse are her parents until she discovers the thruth. After that, she tries to discover more about herself.
. Melissa's grandparents are Zeus, Hera, Maleficent and Hades. For being adopted by Percy and Clarisse, she gets Poseidon, Sally, Clarisse's mother and Ares as her grandparents too.
. Melissa has a sister called Chloe. Chloe is the real daughter of Percy and Clarisse. She inherited her mother's temper and Percy's powers.
. 2 of the smartest characters who everyone thought that were good turned out to be villains: a goddess and her daughter. They both want to take their revenge on Clarisse for her stealing Percy, one of the most powerful demigods, who "this daughter" would have had wrapped around her little finger if weren't for Clarisse and Selena (the goddess not so ordinary).
