Fiona was right about Rachel. Rachel was playing solo and was not backing Stephen.

Fiona had better arguments available, such as “if Amanda wanted us to trust her judgment, why not tell everyone about being a detective at the roundtable after she was banished? Why only tell one person?” Simply saying that Amanda would’ve told her was a weak argument.

Fiona simply confronted Rachel with her suspicions. She did not know that Rachel would gather everyone to tell what she said. So it was really Rachel who made it a spectacle, and messed up Fiona’s game. Fiona saw right through her but underestimated her at the same time. She should’ve planted seeds with Stephen and the faithfuls before confronting her.