Originally Posted by sweetpeasbowtique
Weeelllll, for my 7 fixin' to be 8 yr. old I use the 70mm. She wore it all day at school and it didn't budge.
I'm just going to add, that it depends on the child's hair too. I can't even wear 70mm bows and it stay in. I use the 50's for my almost 7 year old dd and 60's for myself, my hair is some thicker than hers. I'd use a variety and see which works for what type of hair. It's amazing that you can get such a variety of sizes in these things!!