Do you ever look after the girls at your house? If you do, you could get to know them better and gradually teach them behaviour which is acceptable to the rest of the family.
I don't think it will do much good to speak to your Daughter if she is oblivious to their behaviour and she will most probably resent it.
Is it rude to not finish a book club choice that was selected by someone else?
what is this behavior called does it have a name?
