Sister's Keeper

A conversation from yesterday....

Girl (to friends): My mom said I can smack my sister if she's not good. See, watch! (Reaches to hit younger sister)
Me: You can't hit people in the library.
Girl: I can hit my sister! My mom said I can!
Me: You're not allowed to hit anyone in the library, even your sister. If you do, I'll have to ask you to leave.
Girl: Fine! I'ma tell my mom you tryin to get me to disobey her. (Walks away, muttering).

And a conversation from today....
Mother: You the woman who told my daughter she don't have to obey me?
Me: Excuse me?
Mother: Yesterday you told my daughter she can't hit her sister. Well, I told her she can! You gonna kick her out for obeying me?
Me: Ma'am, it's against the rules for anyone to hit someone else in the library. (I pull out our written rules and show her where it says that any violent behavior will not be tolerated).
Mother: Fine! I'ma have her go outside if she has to hit her sister.
Mother storms away.
I drop my head and bang it against the desk.