earlgrey, I can so empathise with you. I have posted many threads over the last 5 years about my dd1 and her terrible temper / meltdowns / tantrums (call them what you want). In fact, only last night I posted this thread about last night's meltdown. Or you can do a search on my name and see what I'm talking about. I, too, have a dd2 (also 7) who just stays quiet and looks worried when dd1 kicks off, and often tries to mediate...
I am lucky in that my dh is 'onside' with me, and we can present a united front. Mostly her violence is directed towards me though. I think it's because we are so similar, and I find it hard to walk away...
dd1 is nearly 10, and I am convinced that her meltdowns are partly hormonal (but she is 2 years older than your dd, so not quite so disconcerting).
I don't really have many words of wisdom to offer. What I have learnt the hard way is:
- walking away is the best way to deal with it - gives me and her time to calm down
- if I get physical with her (not hitting / smacking, which I don't do if I can help it; I'm talking about things like trying to restrain her), it enrages her even more, and makes the situation escalate
- we have talked about things when we are both calm, and talked about how she should deal with her temper. Not really made much progress on this one - it's really hard for her to stop and think when it comes on.
As I say, I don't know whether I can offer much helpful advice, but it has been good for me to know i'm not alone, and I hope it helps you.
People outside the family look at me as if I'm mad when I tell them she has such a strong temper - at school she is a model pupil, she is polite and well behaved everywhere...I guess she feels 'safe' to let go with us.
She is in yr5, but dd2 is in yr3, and I, too, have been told that it is a 'funny' year for girls - indeed our school has brought in a programme of extra pastoral care for the yr3 girls this year.
Feel free to keep talking with me - us mums of strong willed daughters need to stick together!