When I met my wife's Kerala (India) family I thought the kids were all assholes. One fellow almost pushed his mother into a big pot of biriyani. I was shocked because the parents didn't really do anything.
But then, a few years later, those same kids turned out to be the most polite, thoughtful young people. I don't know how it works, but over there they basically just carry on around the children, and they somehow turn out fine.
It sounds like you're doing everything right. Just keep modelling good behavior. I know it's hard, you're doing great.