Ok we have similar problems with DD, who is diagnosed ASD. we have a router which has a guest log in and a house log in - with control via an app on our phones. So if DD starts being violent, or whatever, we can simply turn off the guest setting which controls all her devices. She only knows the log in to the guest wi fi, and its different to the one all our devices use.
And, I think I have said this before, but she really does need to see someone at CAMHS for this behavior as imo it is NOT that of a NT child.
And, Im not being unkind here, just reminding you that you have already warned her in the past that you would call the police if she was violent to you, again? But here we are, she's done it again and you didn't call them, did you? And she has actually hurt you?
What is that telling her? That what you say is just talk.
I would call 101 and ask to have a chat with an officer, they might come and talk to her, and tbh it might just help?
I sympathise, I really do, its very hard indeed and you have done so well to get your Mother out and move, but honestly your daughters behaviour needs to be assessed and the violence and bullying she is doing to you HAS to stop.
And I wouldn't be giving her ANY gadgets AT ALL, after last night. She can use a laptop at school and if it causes her problems with school work, well that's the consequence of poor behaviour choices! And Id be telling the school exactly why she has lost access to the electronics at home.
Do not keep this behaviour a secret, I know its hard to tell people but seriously you need to get some help. 