It is developmentally appropriate for kids to explore their bodies and some kids will self soothe that way.BUT it can also be a sign of sexual abuse and with all the risk factors she has..who knows.No other kids in family.. she splits time between mom and dad..another risk factor as apparently mom has a bf in the home now. I truly hope its nothing.i have been around long enough to know that CPS won't do anything UNLESS dad has a record..which given the dui's, tattoo horns, and violence on mom..he probably does have.Why he has any custody of her at all ..you'd have to ask the great state of California.