When I was a size 12, I had a flat stomach and tiny waist. Hips and bust were a 12. Because my bust continued to expand beyond what I considered reasonable, I couldn't get hold of women's tops to fit over them, without the rest of me being swamped. Alternative clothing at that time, whether it came from Black Rose in Camden, Cyberdog, or from skater shops and Punky Fish, were not made for people of my shape. I was an hourglass.
These days they make amazing clothes for many sizes and shapes. But I'm now a 22. I gave up ever looking nice and being taken seriously and not having my size and shape ridiculed or letched over, I would only wear men's hipster boxers and baggy clothes.
And I let myself go big-time because people made fun because I looked bigger than I was with my buxom frame under baggy clothes. I also didn't understand what buxom meant etc, so when people commented on it I thought I was being called fat. I got called big a lot. I actually wasn't and have photos to prove it.
So in the present, I have a friend who post eating disorder has crept up to nearer a size ten which is healthy and good for her. She is absolutely tiny, also in height. And not built with the same shape as I have. So sometimes I've had to bite my tongue when she's spoken, but we are built differently anyway so I know what's not the norm for her.
I remember feeling some fat rolls on my back if I bent backwards a bit, arched my back sort of thing, when I was a teen. I guess it was normal but I was convinced you had to be taught like a ships sails otherwise you were fat and disgusting.
I don't think OP is BU to mention her weight etc, it's not her fault if her friends are bigger. They should all be able to talk about it together or shut up and not mention it. No one has the monopoly on this