Where is this from? I’m going to be honest, I’m dubious that this is child abuse. Or at least, dubiousnin the sense that it depends on how she does this stuff and how much her demands on him conflict with social norms. Making him wear a dress at school would seem to qualify as abuse because it’s putting him in an impossible position if he just wants to wear boys clothes and avoid being made fun of. But I don’t see how forcing your kid to wear a dress at home is anymore a form of child abuse than forcing them to wear certain clothes for church, or telling them they need to change out of their pajamas even though you aren’t not leaving the house, or telling them they’re bad or might go to hell if they don’t behave as their parents want them too, or that they should feel ashamed of saying or doing this or that in public.
It’s really about whether or not she is putting the kid under a great amount of stress due to conflicts of interest between public social norms and the expectations of his mom. He has to choose who to please, and either way it’s likely an uncomfortable outcome, and it is really the result of his mom’s behavior.