Search Results: bitchy cousin

So today I was struggling with my math assignment and since we're both in the same class I decided to check her answers when she was gone. I wasn't going to copy her answers down word for word, I just wanted to see what I was messing up on. When she came in the room she was pissed and she told me that her brother saw everything I did, and that she told her parents what happened which is my aunt and uncle. I tried to apologize but I know something like that can't just be forgiven. So now I don't know what do, and she's making everything awkward. She won't talk to me, and she's avoiding me the best she can. I just want to know if there's anything I can do to fix this, and if there's any way I can convince her to forgive me? Anything helps! Thank you. We're both girls by the way. And what she doesn't know is that I can tell she's been bitchy to me lately and that I can tell she's acting immature so I told my parents about it, so I might just tell her that.. Since that's why I can't talk to her about everything/anything I want to.