How do u now when a girl likes u sos plese help me?

Wow. Coming from a girls point of view, I think I can understand what's going on. I think she likes you, and like you said, also really likes her boyfriend. She probably can't decide between you two, so is sticking to her relationship to be safe. Also, if she's never broken up with a guy before, then maybe she doesn't know how. One things for sure though, she likes you.