Thin shaming mothers keeping fit

Some women have a bad habit of discouraging others especially when a mother is trying to keep fit, she is usually thin-shamed that she should put on some flesh rather than spending her time staying slim.

I believe every mother has a goal on how she wants her body to be; therefore it should not be any other woman's business if she gets fat or thin; except if it poses as danger to her health.
Has anyone experienced anything similar?

I have never really heard of this term or concept, but I can see it occurring in some circles. I think I was "thin-shamed" when I was younger, and constantly told I didn't eat enough and had poor nutrition, etc.

Now I eat "properly" and weigh a whole lot more. I actually have better self esteem now, but don't look as "good" as I did before. So I can see how people can thin-shame if they are thinking someone is perpetuating unrealistic body image ideals for women, by starving themselves.

It's a touchy subject too because people come in all shapes and sizes, and a weight that is easy for one person to maintain, might be very hard for another, just due to their different makeup.