Determination sometimes isn't a good trait to have

Last night Addy and Sadie the dog were in the living room watching Elmo. This is our nightly routine when we get home from school as I get dinner ready. I hear Addy WAILING and I run in there to investigate. She is so upset that when I ask her what's wrong she can't even talk. She just wails. So I said "Did Sadie bite you?" More crying. Now I'm freaked thinking that my sweet puppy has turned into cujo so I look at Sadie who is cowering in her bed with this dejected look of guilt on her face and give her a stern what did you do look. Then I notice the cookie. Addy's cookie is half gone and it doesn't look like she's the one who enjoyed it. AhHA. So I ask her if Sadie ate her cookie and I get a mumbled cry and a nod and then a whimpering "ess". I decided to discipline Sadie by saying "NO Sadie you don't eat her cookies!" which resulted in more Sadie sulking. This didn't resolve the issue though because then Addy runs over to Sadie and yells "NO! NO!! COOKIE!! NOOOOOOOOO!" as she tries to PRY the cookie from Sadie's mouth! Poor dog.