User blog comment:SayuriDarling/The Mark of Athena Official Discussion/@comment-5812567-20121215010229/@comment-5881112-20121220053855

I think that Gaea does not need Greek demigods because when she couldn't have Percy and Annabeth, she said that Hazel and either Leo, or Frank would do too. She also gave Piper the chose if Percy of Jason died, so either of them would work.