To speak, or not to speak...

This morning, I took the girls for Donuts at our favorite local donut shop. As Claire, Ely and I were sitting there enjoying a long john, pacifier and diet Dr. pepper (respectively), a mom walks in with her two kids, a boy and a girl. The boy quickly places his order, but the little girl - probably about 8 years old, is obviously kind of shy, and mumbles inaudibly to the server, and then turns to her mother. Mom immediately becomes irate, and loudly chastises her daughter to "Not be shy". The poor girl was completely embarrassed. Every mom bone in my body wanted to shake the woman for being so demeaning to her child. The Christian part of me (I'd like to think that all of my parts were Christian parts), was thrown. Do I say something, and risk making it worse, do I say nothing and basically validate what is going on in my abstentia... Right or wrong, I did nothing. So this brings me to my question for the day:
What would you have done?
What would Christ have done?
St. Francis is attributed with the charge to all Christians that we are to "Preach the good news of Jesus Christ to everyone we meet, using words if necessary." What would that have looked like in this situation?