Choose Her Friends
When you have a toddler, she hangs out with your friends' kids as you have a mommy gab session. Oh, those simpler times! After age 5, your child will naturally start gravitating toward certain children, for better or worse.
What to do: If your child starts hanging out with friends you're not crazy about, step back. Try to see why your social butterfly joined a certain group. Maybe you don't understand why she spends time with that loud-mouthed buddy, but for her, it's a way of becoming more extroverted.