[quote=@pyroman]
[@Burning Kitty]If I might ask, what does "She" know? I'm assuming it's emma, but I don't know what Booker said to make Rosemary think that, or come to that conclusion.
[/quote]

Rose Mary was referring to Emma knowing about Rose Mary's sexual attraction towards Emma.

The rest is her sprouting conspiracy theories and being paranoid. She is regressing to the way she was on the streets, a paranoid conspiracy theorist who trusts no one.