Wow, Alaskan! I would probably offer for my MIL to touch my belly if baby was moving (although I haven't), BUT if she asked DH and NOT me, I would have something seriously hateful to say before he could even answer.
I'm 5'2". A big belly on me probably looks a bit bigger than on someone, oh say, 5'9". I am starting to get that look when I'm out in public like "omg, if I speak too loudly that baby is going to come!" I went to an annual consignment sale with my MIL Saturday. While the lady was checking us out, she asked when my baby was due. I said "the end of April." Her eyes bugged out of her head and she yelled "oh, you're going to have a BIG baby!" I smiled, but my response was less than friendly. It went a little something like "yeah, he has always measured a little small on ultrasounds. I don't think he's going to be ginormous. And I wasn't SKINNY before he came along. That's not what I want to hear as an expectant mother."