I guess I have a "mommy look"

Yesterday morning I was changing Sarah's diaper. She has regressed in the potty training since Ben was born, but that's another story.... She was squirming all over the place and I was getting frustrated. I looked at her. I didn't think I was giving her any particular look, but she suddenly said, "I dood dirl [good girl]". I either have a "mommy look" or she can read my mind. I said, "You're not being good" and she said, "Yes, I am!" I'm afraid I don't have a chance with her because she cracks me up!