Yes I do try to avoid those types of people as much as i can in life. She seems to have her own issues and im sure your not the only one to get the cold shoulder from her. I used to have a room mate down stairs that would be nice to me one moment and the next give me the cold shoulder. I took it personally and it effected my mood. I hope you can do what you can to avoid her as much as you can and relize it's her not you.