Ex daughters-in-law: did you drop mother-in-law contact when your kids were grown up?

From the day we separated I have never seen my ex mother in law. I never had a good relationship with the in laws so felt that it was down to my ex to see that the children saw his parents. He used to have them every other weekend so had plenty of time to take them for a visit. Over the years the children had to listen to her run me down constantly. On day when my eldest was about 17 he had had enough of all the bad mouthing and let rip at her. Her told her that if she didn't have anything nice to say to say nothing at all because she must really hate all her grandchildren as they are half mum and half dad. She never got over that had has refused to go to my children's weddings and is now missing out on her great grandchildren. There comes a time in life when our children become adults and make there own choices. We may not agree or like them but as parents we have to respect them.