User blog comment:Percy Jackson12/The Seven/@comment-4405022-20111016160735/@comment-3146930-20111016163310

A lot of things werent mentioned in the books. Heracles is a god, yet he is never shown on Olympus, Calypso wasnt mentioned until The Battle of the Labyrinth, information can be released at any point the author picks. All that has to happen in The Mark of Athena is for someone to say "Metis is Athena's mother" and it becomes mentioned. And yes, Wisdom's daughter could be Athena, it could be Annabeth, and it could be someone else. But anyway, if Annabeth is going to hold them back, why would she be a member of the 7? All we know about Annabeth in the next book is that she will have a hard choice. For all we know that choice could be to step down. I'm not saying she is or isnt the last of the seven, I'm just saying that it might not be her, we dont have enough information