At this point in my life, I do go to the gym regularly. I still don't look like that. I don't have the genes for it. And I would be very surprised if she hasn't had some work done -- very few (almost no) women can have that little body fat and those boobs. Boobs are made of fat. For the most part, if you want all of your body to have almost no fat, and you want boobs, you have to go buy the boobs. (no judgment for those who make those choice, just being frank about reality)
Anyway, my youngest is 16 and my kids are both doing great. When they were little, it was a different story. One of my kids is on the autism spectrum. My husband travels a lot with his job. I used to stress eat.
OK -- I said it. Rather than reflecting "self discipline," my body reflected that I had more on my plate than I could handle, and I didn't have a support system. So sometimes I ate complete crap because it made me feel better, and I had few other options.
Things I didn't do -- yell at my kids, leave them less than stellar care, check out of my family either physically or mentally.
Now, it just makes me sad to think about those days. I'm glad they are over, but I don't feel any judgment for myself during that phase of my life, or feel that I need to make excuses for it. It's just what was going on.
What I see if the caption of the photo is a lot of judgment, and a complete lack of understanding that some people are dealing with things she isn't, or simply have other priorities.
Or even that "fit" looks different on different women. Here is a link to an article called "why you don't look like a fitness model" that has photos of women Olympic athletes. They are all in shape (and could bet her butt in whatever their sport is), but they don't look like her: