When my son was about five he became facnsiated by nail polish. I never wear it on my fingers but I do paint my toes once in a while and I guess this made a big impression on him. It was all he talked about for days. I told him that we could paint his toenails too if he brought home a week's worth of good behavior reports from school. For three weeks he was a perfect angel at school and for three weeks he got his toenails painted. Then he got bored with the whole concept and decided it was more fun to be a stinker at school than it was to have pretty toenails.Nowadays we're using painted toenails as a reward for the three year old. It's amazing what this kid will do for a little dot of nail poish.I'm pretty disturbed by the sexualization of children (well, girls especially) in our society but I don't see nail polish as being a bit problem in that regard. I guess it depends on context. Bright red, inch long fingernails would be a problem. A dot of blue or green or pink on her toenails is just some harmless fun (in my opinion). It's just like when she uses her doctor kit or her play kitchen or her pretend laptop or when she nurses on of her baby dolls. It's just a fun way for her to get a little tatse of playing grown up .