Out of Control 14 Year Old Granddaughter - HELP!

Where to start???

My daughter has 3 daughters of her own, the middle one has, since about 2 years old, had terrible tantrums if she doesn't get her own way, and all three of the girls have learned that if they continue pestering and shouting for what they want their parents will eventually give in for some peace and quiet. My daughter has tried many times over the years to get a grip on this situation, but her now ex (they separated a year ago), undermined her at every turn for a quiet life. Since the separation, things have been terrible, I won't go into the details as it's really not necessary, but suffice to say that the children have chosen to live at both parents houses at various times, playing one off against the other, and when they have a row with one parent, they stomp off to 'live' with the other one.

On Friday evening we travelled for 4 hours to stay with my daughter for the first time since moving away earlier this year, we used to live on the doorstep and have always been there to give support, but had just got to the point where we felt we'd given support throughout what we thought was going to be the most difficult part of the child raising, and as my health is not good, it was a case of now or never. Sadly, it's proved to be the worst timing ever, as it's now that they need us more than ever, and we're not around, but again, that's another story. Anyway, trying to keep this as short as possible, yesterday the 14 year old, most difficult one of the three, woke up in a bad mood, and was very argumentative with her Mum right from the get go. In an attempt to ease the situation, I tried to distract her by asking is she would do my make up for me, which seemed to brighten her up, and went and had a lovely long chat with her in her bedroom, during which time she was really lovely. However, a couple of ours later all hell broke lose when her Mum asked her to do a nit treatment as we'd discovered earlier in the day that her elder sister had got nits. She immediately said that she wasn't doing it, she'd already washed her hair once, and wasn't going to do it again, and it wasn't her that had got nits, etc. Things went from bad to worse, and she wound herself and her Mum up so much that they were shouting and screaming at each other, she even taunted her Mum saying 'coming on then, hit me, you know you want to'. At this point my daughter asked me to intervene as she felt helpless to know what to do. My granddaughter's have all had a healthy respect for me since they were tiny, as I have always given them clear boundaries, and they know what I will accept and what I won't. So I tried to reason with my granddaughter, but again, she continued to shout and scream, I pushed her out into the back garden in the hope that getting her away from her Mum and the rest of the family that were present - my daughter's new partner, who'd already suffered a dreadful verbal onslaught from her, my husband, both of her sisters and my daughters, partner's two boys, plus a little boy from next door. When I pushed her out of the door, she fought me but I was able to hold the door closed, and hoped that when she realised that she wasn't going to be allowed in until she calmed down, that she would re-gain control, but no, instead she began kicking the glass conservatory door. I did see it cross her mind that this was a dangerous thing to do, and so she stopped before she hurt herself, but the out of control screaming went on, and on, and on. My husband warned that someone would call the police as you could hear what was going on a long way down the street, but NOTHING stopped her. Eventually, when my daughter was crying and shaking like a leaf, she decided that she just couldn't take any more as these temper tantrums have been getting progressively worse, and her eldest daughter called her dad to come and fetch all three girls. In the meantime, I'm afraid I tried the age old remedy for hysteria and actually smacked my granddaughter's face, but sadly she was fighting me so much that I didn't manage to get in a good enough slap to bring her to her senses. Now of course, I know some of you will say that I shouldn't have done that, but you weren't there, and the situation was truly out of control. I lived with parents who fought violently throughout their life time, and yet I have NEVER seen anything so frightening in all my life, and am convinced that if no one can help us to get a grip with this child that she will end up hurting someone, or maybe even grabbing a knife and stabbing her mother, given the right circumstances, and no, I'm not dramatising!

Eventually the girls Dad came and collected them, but he had no better luck with her than we did, and meanwhile the others were getting involved feeling hard done by that they'd been sent to their Dad's. By mid evening all three girls had rung and text saying they wanted to come back, but not one of them apologised for their behaviour, and so having failed to do so, their Mum refused them, which immediately resulted in more tantrums. I should perhaps say that my daughter is a tiny little thing, 5 foot tall, and weighs less than 7 stone, in fact she and the middle daughter are of similar build, and having seen the strength of my granddaughter yesterday, if it came to a physical fight between the two of them, I really don't know who would come off worse.

In short, my granddaughter's tantrums are totally and dangerously out of control and we need help, but haven't a clue who to turn to, as on previous occasions my daughter has sought help from her GP who referred her to the school, but the school took so long to put anything into place, that by the time they had it was the long school holiday, and so it all ended up being put on hold, and ended up being pushed to the kerb. So if anyone has any advice, we'd be extremely grateful.