The tween/teen years are tricky parenting geography, especially with your oldest child. How much permission to grant, what are the kids ready for (and you! what are you ready for?), how to balance freedom + protection???
So here's an idea we tried: Years ago when Lauren was around 9, we started a notebook conversation between us. At the time we were in a rut where I seemed to be finding much more negative than positive things to say to her (of course now I can't remember the reasons or the issues or why they seemed so important to me...) and she was getting moodier in that hint-of-adolescence way. I had a bunch of blank books so one day I grabbed one, wrote her a note in it, and left it under her pillow. Then she wrote back.
It's been a crucial thing for our relationship. Recently I got it back out again on an evening when neither of us could really understand where the other was coming from. We both sound better in writing at those times. Friendlier and more calm.
Our guidelines are that we can say anything or ask anything, we won't correct or critique, and (my personal commitment to myself as the purported adult in this whole thing) I try to say positive things each time.
And confidentiality, of course. I won't quote our exchanges here but I'm sure you can imagine them. Sometimes she just asked what a word meant, sometimes I simply praised her efforts at trying new things. Other times we passionately defended our points of view or begged for understanding (or forgiveness!).
As a bonus, we have a terrific chronicle of our relationship. I look back and realize how ridiculous my expectations were at times. Lighten up, Annie, I remind myself. Most often, though, a re-read of the notebook increases my compassion for us both + shows what I've hoped all along: we're both doing the best we know how to do.