Am I right to be mad at my MIL or is it just hormones?

So I only see my mother-in-law every couple of months and I went to her house today and the first thing that she tells me is that I'm starting to look pregnant in my face now. I'm 27 weeks and have only gained 18 pounds, so it isn't like I've gained tons and tons of weight for her to say something like that. I take that as calling me fat and I think it is extremely disrespectful. Do you guys think I have the right to be mad or am I just being overly emotional?