Look, the reality is that muuu doesn't just suffer from gender dysphoria like the rest of us do; she also has a serious case of body dysmorphia. It's a cognitive dysfunction. Nothing that you do or say or show her will change her mind, because her perspective is not a rational one and therefore won't be receptive to reason alone. It's like anorexia (which, apparently, she also had): Anorexics have a severely distorted perception of their body image, and no matter how thin they are, they always think that they're not thin enough. What they see in the mirror is literally warped to them, the same way that their way of thinking is warped. Give them examples of attractive, famous healthy-weight or curvy women, and they dismiss your examples without another thought.
But an unhealthy body image is NOT at the core of anorexia; it's a symptom of a much larger and more complex problem. I've recently read that one common explanation is that many/most anorexics feel totally out of control of their own lives, so they obsess about one thing over which they feel like they have some control. Everything else may be out of their hands, but at least they can always refuse/decline/avoid eating. muuu says that she's at a fairly healthy weight now, thanks to some treatment for her anorexia, but what seems clear is that the original problem(s) at the core of her anorexia have not been resolved and are now manifesting hand-in-hand with her gender dysphoria. Please take a look at her other posts here and in other threads. If you read closely, doesn't everything sound like the words of someone who feels totally out of control?
Frankly, what she needs is not so much the support of fellow trans people on a forum like this. What she needs is to find a way to get professional psychological/psychiatric help again. Otherwise, she'll just continue down a dark path with her dysfunctional thoughts, a path that will likely end in tragedy.
