Young couple goes on van tour of US, boy comes back with van - no girl

while it's notable that you want to protect your grandchild, i think your message is a bit convoluted
essentially you're saying "i don't have an issue with violence, i just don't want my kid to be the target"
and i think it's the violence/punishment dynamic that needs to be addressed no the 'identifying the proper target of violence' dynamic
I understand your response. I am not in any way a violent person ; never had even been in a fist fight.
But on the other hand they did not know that. My way is just to let them know to think twice before striking a woman.