What should I do???

Brie

So there's this girl in my plus block which is my school version of like I guess a study hall and she's really mean. I've always been nice to her and I knew her before high school because she was in my Girl Scout troop and she was so awful and was bullying me so much that I actually quit because of her some of the other girls. I don't know what to do about it because your stuck with the same plus block for 4 years so either I switch plus block and completely ruin my already complicated schedule or I find some way to deal with her. Help please!!!