Isn't 4 a little young to petition for name change?

Out of the blue, my daughter very bluntly informed me on the way to school this morning that,
 
"When we are in the car, I shall be called Emily. My name is never again Ava while I am in this carseat, so please don't call me that. Got it?"

I contemplated responding with something like:  

"Ok, well if that is the case, then anytime between Fridays at 5pm and Monday mornings, I shall not answer to 'Mommy' nor any requests to wipe a runny nose, cut up a piece of chicken at dinner, bring a cup of water at bedtime, help tie shoes, change poopy diapers, put band-aids on boo-boos, be the time-out police, or wipe a bum. Also, no laundry, cleaning, cooking, household errands, vacuuming, dusting, dishes, or making beds during this time-frame. Got it?"


Lucky for 'Emily,' I am a level-headed Mommy and simply responded with a smile and a nod: 

"Of course, Emily. You got it!"