I'm sorry the in-laws are using the kids like this. This shouldn't be happening. If they have a problem with you, it should be between you and them. The kids shouldn't be involved at all.

Unfortunately with a divorce, there's always hard feelings, and the inlaws always feel like they're justified in getting involved. Well, they AREN'T. It has NOTHING to do with them. They need to keep their nose out of things. I know they want to "protect" and "back=up" their daughter, but I'm sure she can take care of herself.

Why not send them an e-mail telling them that if they have any problem as far as the children go, to refer back to the divorce agreement!! And anything else, leave the children OUT of it, or else they will be speaking to your attorney!!!
They cannot keep using the kids as pawns.

I wish you the very best --- God bless and take care. Hugs, Lee