People respond differently to death, some appear to be callous when inside they are hurting badly. Grief looks different in everyone. I do think what they did was certainly tacky and trying to shift blame is the problem I have with it.
I accidentally killed a woman when I was 19. It was a ridiculous thing that never should have happened and her and I were in the wrong place at the wrong time. My response was more sex, more drugs, and more alcohol. I was forced back to work immediately (we were prostitutes that had been trafficked to a particular place).
Now, twenty years later, I still am processing it and it will stay with me forever, but I am sober now. I consider sobriety to be an important way to honor Amelia.
As far as body shaming, it depends. I don't like how frequently "narcissist" is thrown around these days, but I also think it sounds like that girl has a mental health issue she needs to be seen for.
Important things to think about for sure.