Theres a good girl!: You are behaving well! You are being obedient or well-behaved!

Whats considered a bad girl?

A young woman who flagrantly engages in daring or unseemly behavior, self-expression, etc. (slang) A female criminal.

What is the difference between a good girl and a bad girl?

__ A bad girl gets what she wants because she goes for it. Good girls can get what they want too, by identifying their desires and being open to expressing them.