I had a long post but got logged out and lost it. This is an attempt to replicate it.
First, listen to what **Lasciel **says. Lasciel is clearly a wise person in these matters.
I am probably not a wise person in these matters, but here, for what it is worth, is my experience. Take what makes sense, ignore the rest.
When our son was about 12, my wife decided that he was more interested in boys than in girls; I came to the same conclusion a little later. It was difficult to put our finger(s) on anything in particular; he wasn’t obviously crushing on any boys, he certainly wasn’t talking about sexuality issues with us, heaven forfend. But at that time we would have put money on him being gay.
We considered asking him point blank, and rejected it. He was private about a lot of things and hated being backed into corners, and it just didn’t seem like a good idea. We decided he’d tell us when he was good and ready. So we waited. And waited. And waited. And he was 14, then 16, then 18 (I guess he grew 2 years at a time) and never said word one about his sexual preferences. And all the while we became more and more convinced that we knew what his sexual preferences were. (Male.) But were careful not to presume or to ask. (This was harder on my wife than on me, largely because she saw herself–sees herself–as the kind of mom whose gay son would feel comfortable coming to her about things like sexuality. She had to resist the urge to ask point blank more than I did. But she resisted.)
What DID we do? Well, we are a liberal family, and we talked a lot about politics. One issue that we made sure to bring up a lot was the subject of gay rights. (It helped that our daughter, who at the time was identifying as straight, was a member of the gay-straight alliance at school.) I don’t THINK it came across as “Every night at the Unwashed household is a gay history lesson!,” though my son may have perceived it that way; but he did hear a lot of “There’s a lot of prejudice against gay people, but that’s not something that we ever understood and we certainly don;t accept it; we are allies in this fight.” In the context of course of social justice issues of other types too. (I recognize this is easier if both parents are on the same page, which we were but it sounds like you aren’t or may not be. Still, I suspect it’s something you can do on your own as well.)
It also helped that we belonged (still belong) to a very progressive church. I don;t know, OP, if you have a religious background, or if you do, what kind it is, but we found it very useful to couch our support for gay rights in religious and spiritual terms: “this is what we believe the teachings of Jesus require us to do.” When our son was toward the end of high school, the church called an openly gay man to be rector (I was on the search committee), and I think the church’s willingness to do that spoke volumes to our son. It’s also true that most of our son’s schooling was likewise in tolerant and accepting environments–he had a handful of openly gay teachers in HS in particular. Again, I don;t know what kind of circles you move in. My son might disagree–I don’t know exactly what his experience was, of course–but I have always been grateful that we were able to surround him with communities that were generally accepting of people who weren’t straight.
Anyway, we continued not asking, not telling, and after a while it became pretty ridiculous as we would have bet just about anything on him being gay, but that was the way it was. And in fact he never did sit us down in that stereotypical way and say “Mom, Dad, I gotta inform you that…I’m gay.” But about halfway through his college years he called up and said “Hey, I’m dating someone”–the first time he’d dated anyone to the best of our knowledge, and we said “Oh, sounds nice. Tell us about…them,” and he said “Well, his name is…” and the news slowly spread through the extended family, few of whom seemed at all surprised when you come right down to it. And though that first relationship fizzled and pretty quickly too, he is now in his late twenties and partnered with a wonderful man, and all seems to be going along pretty well in his life.
Now. In no way am I saying “This is the recipe for how you deal with a child who might be gay.” People are different. Families are different. For all I know, maybe if we’d asked our son point blank back when he was 12 that would have been exactly what he needed. Maybe that’s what you NEED to do with your daughter. I do think, though, that we did some things right, and I would say those included a) given who our son was, not pushing; b) making our support for “the cause” clear but not personal; and c) surrounding him as much as possible with people who could be role models and/or allies. As I said, your situation may vary, but I’ll offer this with all humility (I hope).
And finally, good for you for taking your daughter seriously, regardless of what twists and turns may lie ahead for her, and for wanting to support her in every way. It’s 2017 and I wish I could say this battle has been won. It has gotten a lot easier than it was, but it certainly isn’t over. In the face of suspicion, prejudice, and even hatred, that parental love and acceptance can absolutely go a long way. That, I firmly believe.