I've encountered vegans who try to force their dogs and cats into that diet. Dogs can kinda-sorta do it with careful monitoring. Cats can't. Seriously, if you're forcing your cat into a vegan diet, fuck you, give the cat to a responsible person.
I haven't, until today, encountered a story of a vegan who was willing to kill her child in order to stay loyal to get delusions. She knew damn well that her kid was on death's door and she kept starving him out of ideological motivation.
It proves nothing to anybody, that you can uphold the highest standards of veganism to the point that you literally starve your own children to death. At what point, does one look at your own child and not realise that something is very wrong and maybe the idea (no matter how strongly held) is just not working and some serious consequences are on the table.
She deserves to be put away.