How to deal with/punish 6 year old DD's tantrums?

[staranise]

I'm at my wits' end with 6 year old DD1, whose behaviour has just been appalling for the past month. She's having regular tantrums where she shouts and screams at me, DH and DD2 (calls us names), stamps, screams, and has started hitting and kicking - culminating in her kicking and hitting me repeatedly (though she's an angel at school).
They last hours and the only response I have is to put her in her room.
They're triggered usually by her not getting her own way, particularly when it comes to TV etc. Hence we've responded by putting away the TV (worked quite well but then the whole family can't watch it), taking away her pocket money (doesn't work as she doesn't have much idea of money), drawing up Golden Rules for everyone (worked initially but not now). I threatened her with no swimmining/ballet lessons but they're empty threats given how much they cost.
I tend to stay pretty calm when she's kicking off but I find her so draining and she's spoiling the mood of the whole house. Right now she's in her room, which means DD2 can't go to bed (they share) plus she hasn't eaten (refused to eat with the others). What do I do? Send her to bed with no supper? Isn't that a bit Victorian? What do you do with bad behaviour at 6?

Sounds rough. Whenever my dd, who is also 6, has a tantrum, I threaten to tell her teacher in the morning which normally heads her off. Or what about a chart with spaces for smiles or sad faces depending on her behaviour and a treat at the end of the week for a certain number of smiles?

And set basic ground rules for behaviour - for example you eat nicely with everyone else or you don't eat. It might sound archaic but she is old enough to make that choice. You are not sending her to bed with no supper as a punishment, she is choosing not to eat her food in a civilised fashion. Why do you think shes being so rotten? Is there anything which could be triggering it?

I don't know - I thinks she's feeling a bit crowded by DD2 (who admittedly does wind her up) but she just goes nuclear immediately - will turn round and scream at DD2 (aged 4) for the slightest thing. It's difficult for me to give them separate time as they're close in age, and DH is never back before bedtime so it's just me dealing with them both plus DC3. Add to that the usual tiredness/strain with the start of school.
Just had a calm chat with her and asked what other things she could do when she feels very angry apart from hitting like maybe she could sit in her room etc. Don't know what to do really.

She's old enough to be learning to control her behaviour or face the consequences and I don't think you should feel guilty about disciplining her or letting her go hungry if that's what her behaviour leads to. What about earning stickers during the week for special mummy and eldest daughter treats at the weekend? Could be something as simple as a walk to the local shop, just you and her.