As a female engineer in the heavy equipment/mining industry I wholeheartedly agree with your comment that this and other tech sites have become hostile anytime gender issues come up.. And I'm not sure why. This community used to be so welcoming of everyone who had something intelligent to say... It seems like the level headed posts are getting fewer and far between.
Good on you for not sticking your daughter into a label. Growing up I liked girl stuff and boy stuff: it didn't matter if it was pink and purple or primary colored so long as I could create something with it
There were a lot of people from both genders along the way that would label me or try to get me to fit there stereotypes of what a girl should be, but growing up with a dad as an engineer also put me in touch with those people who encouraged me and told me how awesome it was to be smart and most importantly to love learning! Nowadays I'm working full time doing a job I love, I have a wonderful fiancÃ© who stays home in a house we own with our newborn son (I'm sure his job is harder than mine some days), all thanks to going into engineering. All those people who told me that I shouldn't go into a STEM field because I was a girl, well alot of them are working retail jobs and still living at home with their parents.
Overall the best advice I can give everyone is that if your son or daughter is interested in something nurture it! Sports or art or science, they all give us ways to grow, and it really doesn't matter what gender you are so long as you never stop learning.