It really depends on the kids, as to how much you share about this site. I know my kids will respect my boundaries. Example - easy child 2/difficult child 2 bought a Lindt white chocolate bunny for BF2 for Easter. I had tried to buy one for him, but she was the one who managed to find one. I told husband last night to put in in our room (BF2 was nearby, I didn't want to explain in more detail, it IS supposed to be a surprise!). This morning easy child 2/difficult child 2 asked where it had been put and when I told her she asked, "Can you check for me in your special drawer? Dad probably put it there and I'm not allowed to look in there at all."
In our case, I DO tell our kids about this site. If she has time I suspect easy child even browses. I know husband does, and it's been a really good thing for us, because he then understands better what I've been trying to tell him (however, never VENT about your husband if you want him to lurk here too).
There have been times when I've asked my kids their advice about someone's difficult child. The kids have been really useful for ideas and as a sounding board.
However - from the sound of your daughter right now, I wouldn't tell her. Not yet. You might hint that you've found some online friends with kids who have similar issues to her, and that we're all sympathetic to BOTH if you (hey, if she's got some sort of disorder then it's not her fault as much as she has been blamed). But you need to get past the hurdle of "my mother is my enemy, she always makes me do stuff I don't want to do," and you "my daughter is a monster, I don't know what to do with her, she is so oppositional it's frightening."
You need to get to a point where you both recognise that there is some positive solution somewhere and you're both working towards it. And you're not there yet.
With help and hard work, you can be. Not "you will be." but CAN. If you do not succeed, do not blame anyone. Not her, not yourself. It just IS. Blame slows you down, slows your thoughts and your energy and makes it even harder to do anything positive. If you try something and it doesn't work, then you have competed that experiment and gained knowledge that can be used (ie "I won't do that again"). Time has not been wasted. You have one less dead end to explore.
We're here for you, we understand. And on matters of faith, a lot of us understand there, too. But we keep it at the back of our minds, not right at the front, because here we have space for all faiths (including non-faith). I'll take advice from anybody, folks! And I want them to stick around on this site, I don't want to make them feel uncomfortable by loudly proclaiming my particular views on faith, unless I'm asked (as in recent post, discussing church and difficult children). For a lot of us from a range of faiths, it helps us cope. For those who choose non-faith, they have their own coping strategies which we also respect.
There is always room for what helps us cope, as long as we can respect that what works for us may not be everybody's cup of tea.
I'm glad you've found us. I really hope we can help you and help your daughter, just as you probably can help us in similar ways.
Welcome!
Marg