, your MIL sounds like my exMIL!
In a particularly ugly incident last christmas that involved her screaming at me, calling me names and pushing me whilst my children were hanging onto my legs says
See, it YOUR fault you son is the way he is!!!
Yep, clearly.
Although I must say I was pretty quick to remark on her own sons history and behaviour.....she didn't like that one bit. Suffice to say I can't really get a break away from the kids because their dad lives with her and the last thing I need is those sorts of comments from the old bat.