In fairness I also would have looked at you like you were crazy had you said that to me. It's really none of your business how your in-laws decide to discipline their children. What is your business is telling your in-laws that their childrens' behaviour towards you has been unacceptable and if that sends them off in a huff so be it, it's their problem (by the way I wouldn't say that to them in front of the kids).

I can't remember if you mentioned it in the first post, but what is your husband doing in all this. It's his family and if it's a delicate situation I would expect him to be talking to his brother and making certain points clear.

Also I appreciate that you are very upset over the behaviour of the child (and in your place so would I be) but slagging the child off over their physical appearance and video recording them to show others is unacceptable behaviour from an adult. Blame their parents not them.