I know exactly how you are feeling, I got a real shock when DD started this at 12 too. I thought it would be later, but that's the onset of puberty for you.

I started to feel hopeless with Belle, I found it hard to communicate with her, she was still my daughter but it was like the door was closed to me - very frustrating.

This worked very well for us -

I sat her down and said that I can see she is getting older and that it might be time we started to treat her like a young adult. I gave her the privelege and responsibilities talk and said that if she did all the things she was supposed to (make her bed, tidy room once a week, feed the cat each day, finish homework) by a certain time each week, she was ok to go out on the weekend. Her activities then would be go to the movies with a friend or have a sleepover etc. We wrote it down as I was not going to remind her and it worked a treat, as she liked not having to ask and she was in control of the situation, either she did it or not. She always did.

Sometimes she would seem really angry and rude, but unable to express it (she also started high school that year). We arranged for her to stick a different coloured post it note to her bedroom door to let me know if she was either - angry and didn't want to talk to anyone, upset and wanted to talk, or just wanted privacy. This was so she didn't run her mouth off and get herself into more trouble. It really ****ed me off when she was rude so it saved my blood pressure a little bit, and she learnt it was totally unacceptable to speak to me rudely.
I also explained that for the time being I was run off my feet with Mitchell (newborn then) and I missed having as much time with her and we arranged to book in an 'appointment' to go somewhere just by ourselves. This actually only happened once or twice as the little bugger kept going out with her friends instead! I know she resented how little I saw of her, but I couldn't change that at the time and she just had to get used to not being an only child.

I still slip into her bedroom when the babies are asleep and have a catch up, she is a very independent 15 year old now, and it isn't fabulous all the time (you should have seen the unbridled eye-rolling and and puffing when I just asked her to do some dishes). It may well amaze you just how SELFISH they can be at this age, I felt really disappointed at one stage, she was such a caring child usually, but when I asked around every single parent said their child was pretty much the same. In fact she was so horrible to her little brother (just being nasty and mean) that he still has never forgiven her and it's mucked up their relationship. He tells her to get lost when she comes home from school, so she is reaping what she sowed - and learning the consequences.

I really, really feel that lots of parents start trying to be their childs buddy at this time and it's not the way to go. Teens want boundaries, even if it is just to have something to push against. They rant and ***** about it, but it's what makes them feel secure and cared about. That is her safety zone that she comes home to. Growing up is hard and I can't fight her battles for her but this I can do.

Just remember, it's not going to be a walk in the park either way, your daughter is starting to stretch into a new skin, she may be shutting herself away in a cocoon right now, but in a while she will emerge a butterfly. It's a wonderful thing to watch.

Good luck with it all, mummy of a young lady !!