AITA for being uncomfortable around a classmate just for their appearance?

I am literally losing sleep over this because of how bad I feel.

One of the classes i’m taking has a very interesting professor who is very big on working in groups despite 90% of the class being notes. We get paired around and do icebreakers all the time to ease the tension, and this is where my problem starts. There’s a girl in my class who, and I really couldn’t care less, and still treat her how I treat everyone else, is extremely overweight. Not just a general larger person, she can’t really get around the room well. Honestly, this by itself didn’t make me completely feel the way I do , but it was also what I learned about her life. She mentioned that she literally doesn’t do anything. We were discussing hobbies and she plainly said that aside from classes she just lays in her bed / “bed rotting” (her words.) We all kinda chuckled and assumed she was exaggerating but she, for whatever reason, was insistent on us knowing that she literally just lays in bed and eats. Ever since that conversation I’ve felt strangely uncomfortable around her. I’m not intimidated by her, it doesn’t make me mad that she lives an unhealthy life, I literally just feel extremely uncomfortable any time I interact with her and I can’t place my finger on the reasoning.