We are a low-to-no makeup household, mostly as a family-culture thing, not really as a specific value. Since they were quite young, we have talked about how the primary function of makeup in adults is to approximate the natural skin tone and color of youth, which is why wearing makeup in one's early adolescence is a bit like gilding the lily. No intrinsic harm in it, but also not nearly as much aesthetic value as one might think, either. Makeup or no makeup is not that important. Healthy habits (that lead to healthier skin and hair) and healthy attitudes (that value and appreciate a wide range of healthy physical attributes) are more important.
I will say that, having frequent interaction with high-schoolers in a cosmetology vocational program, I do see some young ladies with very tasteful, age-appropriate makeup.
Bottom line, there's no specific age in our house, but no one's asked for it yet, either.
