I understand how you feel.. it’s mostly humiliating.. at least it was for me. I have wide hips, while my aunts, mom, grandmom and sis have almost unexistent hips.. and they were (still are) thin (in an average way), so I kinda grew up thinking that thin/small hips was the “normal” thing to have, and that I was not. (on the other hand, they also commented how awful were the big hips my dad’s sisters have) But the bad part was that my aunts were always making comments like: wow, “oh god, look at those wide hips!” (and in front of my boyfriend!, so I kinda wanted to drop dead), also said stuff like “you’ve got a butt, a weird shape, but you’ve got it” (this was when I was around 12!). Once one of them told me: your boobs are looking big! must be because you’re fat (I was kind over weight in that time, not too much though), that’s the only way you can have them. I always did like I didn’t hear, or laught, but those things really hurt me, and when my boyfriend realized the kind of things they said (I must be fair, it wasn’t common, but the moment I least expected they could say something like that) he got very angry at them, and told me to tell them to f*** off… anyway, I don’t know if I was over reacting, since I was very young (17 by that time), but once my aunt’s husband said something unpleasent about my weight, and I got really mad and made fun of his ugly nose! well, guess what? nobody ever said a word to me again! and it’s been 8 years… Anyway, I’m thin again, but I always remember those comments! When I was in high school I was also thin (never stick thin, since I have an average bone constitution, which I really love, by the way) and with my wide hips, which I thought where unattractive, and one day a friend of mine told me “I wish I had your hips! look so great with your small waist” and I got home, look at my self in the mirror and realized I DID look good… Anyway, at a point after I finished high school I gained a lot of weight (a lot for me, at least), around 30 pounds, and my mom all she did was telling me I had to loose weight (Like I didn’t know it! but I was having anxiety problems and eating a LOT of chocolate and sugar, also didn’t help that my boyfriend (who was very thin by then), told me to stop worring about my weight and be happy, that I looked gorgeous anyway)
Anyway, I recovered my dream weight again, and I know I’m not plus size and so perhaps you’re not very interested in what I can say about it, but I just wanted to share these things! Because they made feel humiliated. And perhaps your Future Mother-In-Law is just worried, as I’m sure my mom was, but I understand perfectly how that can make you feel!!
Hope you can find a nice solution for your problem!!