User blog comment:SayuriDarling/Full first chapter of The Mark of Athena/@comment-3146930-20120601221322

This is something I thought of today. Athena is very smart and like I said below, Athena tends to measure the odds over things like gut decisions. We also have the Greek and Roman demigods who hate each other and are one mistake away from killing each other, so not good odds of them working together. Athena may be upholding Zeus' orders to keep the camps apart in order to prevent them from killing each other.

However, as we've seen in the other books, the other gods don't agree with Zeus' order to close Olympus. It is possible that the other gods don't agree with Athena and have started working against her, possibly even expelling her from Olympus. If Annabeth actually had to choice between helping her mom or helping Percy, the choice could stress her out and she could run off and do her own thing, like come up with some other plan to stop Gaea. Frank would have to make Percy let her go and Annabeth would follow the Mark of Athena through Rome, then causing the mark to appear all over Rome as a sign she was ok