I think once she saw how Clayton really lives, she got the ick.
You’ve been dating for 2+ years, suddenly when she lands, no sex in a month since she’s got there? Something seems very off about that. It’s even weirder that she acts like it’s not a big deal?
To make things worse, she mentions that she can “find another boyfriend”??
She doesn’t seem motivated into this relationship anymore.
It honestly sounds like she was never as committed to this as him (and I don’t blame her) which is why she didn’t tell her parents. She probably saw this might not be her ideal situation and want to return home, so she left the door as open as possible.