Hi
SallieI am glad you found us. Welcome to the group. There are many members here in situations similar to yours including grandparents whose parents (whether children or in-laws) make having a relationship with their grandchildren difficult. I am sure some will be along to share their wisdom and experiences.
You are in tough situation but it is not hopeless. Already you are committed to improving your relationship with your daughter in law. There are communication skills you can learn that will help. I think a good place to start would be validation. Here is a great article about what that means.
Don't Be Invalidating I hope it helps. We are all here for you.
Hugs
Faith