Kinder drama

I need help responding to a parent. Most of the parents I hear from are sure their kid is an angel and everyone is after them. Often their kid is half the trouble. We have a lot of behaviors in our classroom lots of hits, pushes and one kid who swears all day in a class of 26. Really, I don't think any of it is particularly unusual for the age group. How do I get them to understand? She says her daughter doesn't want to come to school because everyone is mean to her or she doesn't have friends. but I think that's more because she doesn't like the lessons/learning. She doesn't want to learn, she wants to roll around on the floor and stick her tongue out at people. I just don't know what to tell her that won't make her more angry. She also threatened to remove her from school; we have a waiting list.