10 yr old sister wants to wear makeup?

my sister is 10 . well going to be 11 in a month and wants to start wearing makeup not like red lipstick but foundation and a Little bit of mascara that's it . my parents aren't sure but she said shell buy it with her own money is it going to ruin her skin or make her break out ? i looked at a whole bunch of websites about it and they said most kids start wearing it at 11 ? how old where u when u started to wear mascara and foundation if you did at a young age did it reck your skin or give you wrinkles and sorry i already asked but jus want to take a voting to c how much more ppl started to wear it young = ) thank youuu