@ The_Blazing_Heart
Seems more like you' must ask her to have a pretty long chat, like... for at least of 30 mins long. And just start on asking why she feels annoyed. Ask if it is because of you, and if so then why, else, ask what is the reason then if not you. You probably have to be insisting, but yet don't push too hard on her when you see that she is obviously nervous.
You gotta have a serious and long enough talk and it also means to be a hard one, sorry :[