Could this face lie?

I don't think Frankie has ever told a lie. The closest she has come was several months ago when we were potty-training and bribing her with M&Ms. She got one for peeing and the promise of an infinity of M&Ms, forever and ever amen, if she would just please, sweet mother of Abraham Lincoln, poop in the potty. She was supposed to be taking just one M&M from the jar and she grabbed two or three and immediately closed them tightly in her fist. I asked her how many she had in her hand and she stretched her other hand calmly out toward me and gently laid it on my arm, saying soothingly, "Don't worry, Mommy. Don't wooorrrryyy." Like I was going to fall in a trance from the well-modulated tones of her excuses and my eyelids would droop enough she could sneak the handful in her mouth.
Her lack of deceit will not allow her to accept a compliment on her behavior without full disclosure. Today I told her I was proud of her for sharing so nicely with her cousin. She immediately volunteered, "But I did take the little blue bike when Sylvie wanted it and ran away with it." She also knows that once she's in bed she is not allowed to get out to play. So when I told her she took a good nap, her guilt complex kicked right in and she spilled, "I put my foot on the ground to get one of my animals. One time. But then I got right back in the bed. One time, Mom. Just one time. That's okay, Mom. It is!"