10 is pushing it a bit, but before 9 (ie before puberty) the only thing we have to worry about is seeing lower half nudity, which miniskirts do not show.

In fact you can see what my point is heading towards, and that the problem isn't the clothes but your collective mentality towards the idea that women should be perpetually (or if not perpetually not until they or 47 years old and past menopause) prim, proper, and free of sexual thoughts.

I should point out that ten year old boys who walk around topless are not chastised.