Who do you think is right in this situation?

I think your completely right. You have to understand friends will stick by friends. No matter if they are wrong, they will stick by them through thick and thin. That is what being a friend is. Yes, at times they have to chose their battles but I think they always took her side, is because they did not like you. Every time you two would have a fight her friends would always say that she is right. I wish you the best and I know that your right.