I keep it simple. use the cold weather in your favor. get the kids ready as best you can and walk them out your front door and do not let mom enter the house leave the whole family outside and close your door on them. she either gets it together to get them in the car and gone or they all freeze in the front yard while mom plays "whos the boss?" with her preschoolers. trust me, the colder it gets, the better the lesson
if they really get out of hand, I would dress both kids and walk them out to the car, put them in the seats (mom can do one, you do one) and again, do not allow mom in your house or even to your door until she can handle the kids alone. I would rather do the extra work of walking them out then let mom drag on the fight for 20 minutes at the end of the day.

Comment