Hi Lefty,
You're right; it's good to get a professional opinion on this. However, it seems to me that all such questions (and answers) ought to be examined on a case by case basis.
I have no children of my own, but I do have a 12-year old niece whom I very much adore. A couple of years ago, she came to my place for a weekend visit. While here, she noticed I had a "Diva David" magnet set on my fridge door. She asked me why the man was dressed like a lady; I hesitated for a brief moment, not being sure how her own parents would want the question handled. In the end, knowing that she's bright, inquisitive, and open enough to understand the basics of gender variance, I did my best to explain it to her. She then asked me (and I should've seen it coming!) if
I was like that too. I tried to see how I could possibly weasel out of
that one; I couldn't. So I told her the truth: yes, I'm also like that... sometimes. But I'm always, and will always be, the uncle she's come to love (she very much sees me as a flesh-and-blood link to her distant father, who lives on the other side of the country).
She seemed to understand. (Her mother's another story, altogether!)
If I'd suspected that she wasn't ready to understand, I wouldn't have told my niece. It just seems to me that some children lead more sheltered lives than others. Perhaps those aren't ready to wrap their young minds around the example set by cross-gendered role models.
My question to you, Lefty, is: do
you think your children are ready to handle this about your SO? If not, when do you think they will? The danger, here, is for them to find out some other way--the lesson learned will be that "this" is something we have to hide from people because many just don't accept it and that, even though you harm no one and are expressing who you are more fully, inordinate regard should be given to what others think.
Case by case. Child by child. You and your SO are the best judges, here, for you know your children best. May it all turn out right for your family!
Love,
CJ