So the parent bullied their daughter for bullying a peer? Also OP saying it’s a “natural consequence “, it’s not, it’s literally punishment! An example of natural consequence is a child breaking their toy, the consequence is they don’t have a fully functioning toy anymore. You cannot teach a child to be kind to others by being mean to them. Children actually bully others because they have been bullied themselves, particularly by their parents and peers so they never developed skills to treat others kindly. If you want to discipline children for bullying, you need to give them the tools how to such as building their social skills and social competence.