My wife and i got a ticket because she was feeding our son in our car....?

My wife and i were on our way home from her parents house and we were stopped at a red light and my wife was feeding our 3 week old son and a cop stopped us and pulled us over and gave us a warning saying it was against the law and that it was unacceptable for my wife to be feeding our 3 week old son in our car and that its private and should only be done at home. Our SUV's windows are tinted and everything. Well now my wife doesn't want to feed our son at all and wants to switch him over to Formula because of this cop and what happened today and that she doesn't want to cause problems and chit. Well how can i convince my wife and reure her that she should still feed and that she isn't causing problems by doing it?