To be honest, you have already crossed a line by involving yourself in how other people discipline/ berate their own children. Yes you are a relative but that doesn’t give you the right to stick your nose in wherever you see fit. You aren’t raising these children and I don’t think you should be judging your DIL and labeling her harsh- what exactly do you mean!? Only she and your son know how to discipline their children, how they want and maybe you have made him feel insecure by your comments hence starting an argument. My advice would be to mind your own business when it comes to other people’s children and family life and be a relative, part of an extended family who is included because they love you and your company. Continue in this road and you will cut off your nose to spite your face.
How do you acknowledge Easter.