I don't agree with what you have described here at all. The mother is doing the girl a huge disservice by allowing and encouraging her to behave in the way you described.
Even though you sound like a level headed woman, there is nothing more annoying than someone who doesn't have children trying to tell you how to raise your child. You mentioned she was a relative. I would try to approach one of your
female relatives that has children and enlist her help if you are
concerned about the little girl.
Thanks for your reply....
I am a mother of two small