I'm going to slowly work through all the posts on this thread. And join it myself. You may have seen my other thread on this board about my 13 year old dd.
Feeling really battered and low this morning. Horrible, horrible scene last night. I lost my temper.
Ended up in a physical tussle. DD on the floor, me practically sitting on her. All witnessed by my younger dc's, her were frightened and upset. I feel sick about it.
And over something so stupid - me asking her to switch her phone off/put it away while she was doing her homework. Her BBM was pinging every 3 minutes with messages. We'd agreed last week at some emotional expense (involved her screaming and shouting) that she won't use her phone/access facebook/go on Youtube while she does homework. She has a big problem with her concentration (which she herself would admit) and a track record of not completing/starting homework, so this is a fundamental thing. She's just started at a new school and needs to get on the right track. Regular homework time and supervision is really key at the moment.
It escalated from me asking her to put her phone away, her refusing and being rude, constant constant aggressive backchat, me raising my voice and shouting, her shouting back at me that my breath stinks and that I was spitting in her face while I was telling her off (and spitting a mouthful of water in my face to illustrate), her drawing my 7 year old (who has ASD) into it. Me taking my laptop away from her (she'd been doing her homework on it) and pushing her out of the kitchen. Her following me around the house, even into my bedroom, trying to pick arguments. In a situation where she is being asked to do something she doesn't want to comply with, her usual strategy is to launch a personal attack on me, which she did.
And I thought, she's not going to talk to me like that in front of my other children, and I went to confiscate her phone. Which was what resulted in the tussle. She then threw a bowl across the kitchen and broke it. Thank god DH arrived back from work at that point otherwise I don't know where it would have ended. I was on the verge of bundling the boys up and going somewhere in the car to get away from her. She smashed a door open and it flew into ds1, hurting his arm. They are scared of her. So am I. 
I took the boys out and came back after an hour. All appeared to be reasonably calm. DH took charge of her, and the rest of the evening passed without much more stress, apart from her marching in to the room I use as my office at 9pm and turning the computer off when I was on it - she had decided she needed to do something on it, walked in told me 'get off, I'm using the computer' and when I said 'when I've finished' she reached around me and just turned it off. She also screamed at DH when he asked her to do something, can't remember what (pack her bag for the morning?) and woke the boys up, then went in and drew all over sleeping DS2's face with a green felt tip pen, which then went all over our only nice matching bed linen......
DH had to get her up this morning. It took half an hour of nagging as usual, and she slammed out of the house without talking to me.
I feel sick about it all.
She's 13. I don't know what happens as a parent when a child just point blank refuses to comply with reasonable requests. You feel like you're going into free fall. I keep having to pull back from thinking - 'well, just do what you want then' and stop parenting her in a responsible way. It's especially hard when you feel victimised by personal attacks. It's so distressing - DH has exactly the same expectations of her that I do, asks her to do the same things. She's not usually compliant with him but will eventually do it. But what he doesn't get is the vicious personal attacks that are so upsetting. She saves those for me. 