> Can't a boy look up to the character and actions of a woman, and vice versa?

I believe, in life, girls can look up to men but boys do not look up to women. I suspect, but am not sure, that is built into the biology of each.

> I have so called mixed-race children and it would be silly to limit them to aspire to be like historical figures that look like them, because I can't even think of one example.

I agree. However, I think that we can make observations that show it does happen. E.G. the non-historical release of the Black Panther movie.