luckies4me,
Please don't take this the wrong way...please. I am coming from a place were I've seen this type of behavior as a child advocate. I was there when "my" child was taken from her home and put into a children's home. I know the behavior your mom exhibited was out of frustration and her past....but, you may want to consider not leaving your son in her care alone...that frustration can easily come back if she's evoked.

Just be careful. And please, don't take this the wrong way, I know people can change, but your child depends soley on you for his safety.