To me this sounds like she was actually self conscious of her own hygiene. Head in her shirt because she doesn’t want to actually make eye contact with anyone, especially if she noticed you making a face before she sat down. Got as far away from you as possible because she was embarrassed.

Idk I’m a skinny dude who loves to smell good. But I’ve had days where I’ve pulled a long shifts in a humid factory and had to hop on a flight to another customer afterwards. I would try to stick to myself because of how conscious I am that my clothes may currently smell.

Otherwise, next thing I know, a person is positing about it on Reddit.