Thank you, everyone, for your wonderful words of advice and guidance.
I have always striven to be honest and open with my daughter (at least as much as possible/prudent... I don't let her know if I'm behind on the mortgage, for example, because she is eleven and doesn't need grownup worries), so I made the decision to come out to her this weekend. Having just confirmed with my therapist this week, I could honestly tell her that I was letting her know as soon as I had some face time with her and I was certain.
My girlfriend and I (who my daughter adores) picked her up at about 7:00 on Friday evening. The plan was that she would spend the entire weekend with us, and I figured that if she had questions or worries it would be better to have her ask them while she was with me. So, we took her to a pizza place and chose a quiet booth.
It took a bit to get through her amazing monologue of the things she had done the week previously, between basketball, writing some new songs, boys maybe "liking" her, and various other topics, she had a lot to say before I could get a word in edgewise. The anticipation was pretty insane, but I think I managed to be reasonably attentive. Finally the moment came.
(Below is what I remember, not word for word, but as close as I can get... I was a little overwhelmed at the time. Probably should have recorded it.)
"I have some exciting news", I said. "It may be a little weird to hear at first, but I want you to listen for a bit."
"Ok, what's up?" she said brightly.
"Well, I want to start off by telling you that I will always be your Daddy. No matter what happens with my appearance, that will never change. I love you, and I always will."
A panicked look crossed her face. "Dad, you're scaring me. What's happening?" *sigh* It sounded so much more reassuring in my head.
"It's nothing bad, sweetheart..." I had to re-factor the discussion in my head, juggling the important point to the front. "You know how I've always been, well, more feminine than your mom?" She nodded. "It's well, because I'm transgendered. All my life, I've felt like a girl. I wanted to do girl things. I've never been comfortable being a boy. But I've always told myself that I had to be. I've been too afraid of hurting other people to think that I had a right to be happy with myself."
"I've been telling you that your own happiness is important, that you should stand up for yourself and be heard, even if it seems like people won't like you because of it. That's important. But, sweetheart, I haven't been doing that for myself, because I couldn't let myself admit that I'm in the wrong body. I've been through a lot of therapy and finally I'm strong enough to realize this about myself. I confirmed it on Monday with a special kind of therapist who helps people deal with this kind of thing."
"So... here's the weird part: I'm going to start what they call transitioning, becoming on the outside what I am on the inside."
"Daddy," she said, "I want you to do whatever you need to do to be happy. Your happiness is important too." Her eyes lit up. "And it *is* exciting."
At this point I really don't remember much of anything except hugging her and crying. Over the next couple of days we went through a lot of questions and answers, and went shopping together (The real me, my daughter, my girlfriend, and her daughter plus her daughter's girlfriend... a real girls' day out!). The only confusion that day happened at a fabric store. As the saleslady was cutting fabric for us, my daughter was as chatty as ever, calling me daddy (which caused the saleslady to look a bit confused as she overheard it), then she said something like, "And my daddy is going to be so beautiful in his new dress. I mean *her* new dress." I'll hand it to the saleslady, she didn't miss a beat. My poor daughter was mortified that she'd used the wrong pronoun at first.
I told her it's *fine*, I've been her daddy and seemed male all her life, I certainly didn't expect her to change everything overnight, and I would be ok if she never changed pronouns. I told her the fact that she loves me is more than enough for me, way more important than what words she uses.
After that, though, she asked if it would be ok to call me "Robin" in public, so it wouldn't be so confusing for people. I said sure, as long as she knows I am still, and will always be her dad.
Anyway, that's the novella. Again, thank you all for your help! I'm sure you'll see bits and pieces of your suggestions sprinkled throughout. I humbly thank you from the bottom of my overfull heart. And I hope that this helps someone out there like I was. Now to come out to my mother...
Love and joy to all!