Sorry to hear about your experience! I this think type of behaviour is appauling because in Western Countries, and most other countries actually, this is not tolerated. As a teacher, we encourage positive reinforcement strategies and the use of words versus a physical approach which is detrimental to the child's self-esteem and sparks patterns of abusive behaviours in their adulthood. I would have personally approached the mother to discuss my displeasure with the situation. I hope your daughter is okay and not affected by this experience.