When I was 12 - going on 13, I started 7th grade which was junior high in my district. About half the girls wore at least some makeup, and about half of those knew what they were doing. By years end, about 3/4 of the girls wore makeup. Remember, most boys develop later than girls. Some boys are attracted to girls that wear makeup, some are attracted but scared, some don't like girls that appear grown up, but a good many are totally clueless at that age. Do what you feel comfortable regardless of how others perceive you, but make sure it is YOUR choice.