Little Girls Nail Party

My Boyfriend's Mom just gave me the idea that I should do little girl parties for painting nails! I love the idea and think it would be so fun... the only problem is, what would the kids do in the meantime while I'm painting the nails one at a time? Would that be for me to decide? Or the mom in charge? She said I should do a party price, and then charge like $7 extra per person. I love the idea, but I think I would need some help! What are everyone's thoughts??