I had all the play make up like Lip Smackers and peel off nail polish (and kiddie perfume until I came up allergic to it) when I was a little kid but then began trying to wear this godawful metallic lipstick in about the 6th grade. My mom didn't allow me to wear make up to school (I could play with it at home, but had to wash it off before school or church), so I would sneak it. Then after the 6th grade play when she took me to Clinique with her to get a make over for my stage make up I started trying to wear blush, mascara, and eyeshadow. She eventually gave in on the mascara, but didn't allow me to wear anything else to school until I got into the junior high. I started wearing base make up then because my skin wasn't very good, and then began to wear eyeshadow. I was allowed that much but she wouldn't allow the black raccoon eyeliner all the other girls wore and I pitched fits about it until high school. She said it looked horrible and of course I realized around about 16 she was right (and by then just about every other girl in the class realized how bad it looked, too) and scaled down my make up though I still wore foundation and powder every day because I was self conscious about my skin.
Looking back I realize I probably made my skin worse by wearing all of that make up daily and of course it didn't look good. On the other hand it all had SPF so I guess I was at least inadvertently wearing sunscreen every day. I now wear light mineral make up and mascara every day, and occasionally a sheer shadow...I think my mom was right to put the restrictions on me that she did but I'm glad she let me experiment with it at home when I was a kid. I still like playing with make up, just without blue metallic eyeshadow or spider-lashes
. I don't see anything wrong with letting kids play around with it. It's like playing dress up.