The other day it was time to wake Sophie up from one of her naps, so Sarah found Emily and the following conversation ensued.
Sarah: Hey Emily, it's time to wake up your sister. Do you want to help?
Emily: Yeah! I'll do the waking, you do the smiling.
Sure enough, Emily ran up to the crib, woke up baby Sophie, and then looked over expectantly at Sarah, waiting for the agreed-upon smiles.