1st - Sarah can wave purposely to her family as they bid her farewell.
Grandma:" Sarah, wave bye bye to mommy"
Sarah: [opens and closes fist]
Grandma and mommy look at each other in bewilderment and disbelief.
Mommy:"Let's try again."
Grandma:" Sarah, bye bye"
Sarah: [opens and clenches fist]
Grandma and mommy look at each other in bewilderment and disbelief yet again
Mommy: "Let's try the 3rd time. Bye Bye Sarah!"
Sarah: [opens and clenches fist]
By now, grandma and mommy are beaming with pride and cheering in unison.