Sometimes when a woman is around someone she's comfortable with, like a close friend, sibling or a relative, they act more like themselves. But when they are with someone and has insecurities about her personality due to bad experiences in the past, she hides it and starts to behave like the exact opposite of who she is due to fear of repeating said past experience. Now, i do not know this woman personally nor do i intend to pretend that i know this is what happened, but she does have a different demeanor ever since she started living with her BF.