Could I have the definition, please?

I have to share a rare comment that was made in our home a few days ago. I know LeAnn has raised some boys that made "Mennonite" comments, but I've never had one come from my children until now. Tavin and Simon were arguing over whose turn it was, or some other rare conflict, and when Simon didn't bow to his older sisters' wishes she said, "That's not very Mennonite."

Unfortunately, she couldn't tell me what made it so, or what would have been the "Mennonite" thing to do. I think she was going for chivalrous, which at this point is a concept that Simon really couldn't care less about when it comes to his big sister!