Doubt it. Some states have "weight discrimishun" laws so the author would be fucked in any of those areas.  Beyond that. It's a retail job, the girl sounds like a teenager/young adult. She'd have to have the funds and evidence to prove that the company fired her for that, and have worked there long enough to be outside of the probationary period to have a shot. Also with retail hams I'd expect company policy against fathate/fat jokes they could cite. Even if she's legally 100% right, it's still unlikely to hold up in court.