I think your post may have gotten lost in the "pile". I check every once in a while for any actual posts about queer parenting (as opposed to queer conception and pregnancy...) and this is a timely one. We have been bringing our six year old daughter to Pride since she was tiny, and she lives in a lesbian household. But I'm realizing that as she gets older, even though we've already discussed these issues repeatedly, she needs to revisit them again at a level appropriate for her development.
For example, last night we were at an outdoor Pride concert, and there was a visibly transgendered person in one of the groups. We have talked about this before - she even had a trans day care provider in preschool - but she wanted to know why this person looked like a girl but had a deep voice. After I explained that some people can be born into a girl's body but inside, feel like they are a boy and then decide to be one (and vice versa) she looked at me with surprise in her voice and said, "You can DECIDE to be a boy or a girl???" Believe me, we have discussed this quite a bit before, but for some reason, it sunk in in a new way. Then, they introduced the gay men's chorus, and she said, "Mom, what's 'gay'?" I was hoping no one was listening, and thinking what kind of self-hating lesbian moms this child has!
But what I realized is, at six, she needs a different explanation than she needed at 3 or 4 or 5, and that kids need information repeated, even if we think they get it.
P.S. You mentioned civil rights, and we talk about that in our house pretty much as the ability for her moms to get married someday. She definitely gets the injustice of that.