Well, it depends who I'm babysitting XD The girl I watch every week is, I've been watching her for six years so she's practically family. She's the one I worked on the avatar with. She loves playing with my avatar XD
Sometimes I watch a couple of the other girls her age at the same time, and they're all friends, so that's nice and fun. The younger three I watch are harder. They're well behaved alone, but all three together are like a hurricane combined with a tornado and a tsunami.

I make my sister help when I'm watching them.
I agree with you on the personality XD Kids get along well with people who are childish enough to understand them more like a friend than an adult, but are mature enough to stop things before they reach a point where something goes wrong.