Shut up, Mommy

Yes, you read the title correctly.  A few days ago when I asked Harmony to pick up her crayons, she looked up at me and said, "Shut up, Mommy." 

Let me set the scene a bit.  We had just finished coloring three beautiful circle pictures for Daddy and a few extended family members.  I thought we were bonding, having a moment, connecting at a level that could ward off teen pregnancy, lip piercing, truancy, and other potential high school traumas. 

 So when I asked my little darling to pick up her crayons, the last thing I expected to come out of her mouth was the "sh" word. 

"Shut up, Mommy." 

She just kept looking up at me, saying shut up over and over again.  I froze and thought, "What would Super Nanny do?"  (Like A Big Kid will be coming out with some WWSND bracelets soon.)

I took a deep breath, sat down with her on the couch, and said something truly brilliant like, "We don't talk like that.  That word hurts people's feelings.  Look at Mommy's sad face.  Even if other kids say that word, we don't.  Blah.  Blah.  Blah." 

She looked back at me and repeated her mantra a few more times.  I said, "Go away from me," which started her crying, and that was it.  Now the most pressing issue were the tears and not the words.

I don't feel like I did a good job at this one.  Since the "sh" word incident, she's also come out with "stupid" and a few other words that I prefer we leave out of our familial vocabulary. 

How do you deal with stuff like this?