What to Do About Rude Co-worker..

Ok seriously im kinda pisssed off right now. My stupid co-worker (shes a girl) shes 23.. Anyhow, shes a ‘bigger’ girl.. Not to be mean, but she’s overweight. Doesn’t bother me at all and I think its fine. But she is really getting to me. A few months back she would always comment on how I eat all the time and bla bla bla…even if I wasn’t eating a lot etc..And not to sound conceided.. But I know im not a big person, and she knows a little about my past/present with my eating disorder (not in detail at all tho) anyhow, today she was like “kari, look..See that guy” and she pointed to this guy that sits near us. He is such a nice person. He is overweight..And shes like ‘his bellys like yours!’ …first of all im thinking… how immature and rude.. That guy is super nice… and 2nd of all I got pisssed because she was comparing my belly to his.. (not to be mean at all) but I mean im really self conscious..And it bothered me a lot.. I know of course my belly is gonna be big, im 37 weeks preggo lol.. But still..I know it doesn’t look like just an overweight belly at all but it still buggs me! Im just trying to remind myself im fine, ive gained 22 lbs and im almost done and haven’t gained in 9 weeks so I know im not like overgaining.. But my head gets the best of me sometimes. She also freaks me out sometimes because I always catch her staring at me! What should I do about this girl? Thanks!