If it were my kid, she’d have at least a year long ban on electronic communication from me (with permanent monitoring permission as long as she’s still under 18 or at home forever after), as well as community service (hopefully on a way to teach her better), and a sincere apology. That’s in addition to any legal ramifications she might face. She needs to learn just how wrong and hurtful what she’s doing is to someone, and that people with disabilities are people too, with dreams and feeling. (On a side note: my kids understand that the deal that allows them smartphones, social media and internet in my home comes with the condition that I get to check their messages, browser history, etc. I specifically don’t pry or read lots of details, but I do check regularly that they aren’t doing anything dangerous, talking with strangers or doing anything illegal.)

Make your daughter apologize to her victim. Then take all electronics from her and get her an abacus for math class.

I am so sorry your daughter is such a sociopath. She needs an internet ban, intensive therapy, and must be charged with cyberbullying. She needs to understand the consequences of her actions before it escalates further.

What's your spouse, parents or in-laws' stance one the matter? I'm not trying to absolve you daughter on the matter, it she should be punished harshly. But this kind of behavior is often acquired rather than innate.

The fact that you are ashamed of your child's actions and not automatically defending her is a sign of good parenting. As others have said, she needs social media and electronic devices taken away, as she has proven that she cannot use them safely. She needs intensive counseling, and needs to apologize in a meaningful way to the child she harmed. Sometimes kids do bad things, despite their parenting. Best of luck, and lots of hugs, OP.

It will take time but you should be able to explain to your kid why it's bad to make fun of other not so fortunate kids.

Kids don't wake up and just be assholes. This kind of behaviour is a process that should have been stopped and corrected long ago.

you should move her to another school, for the other kids sake, but mostly to get her out of her social group that influences that kind of behavior. and talk with her about it. :)