Jim, don't get me wrong, you are navigating these choppy waters better than can be expected.
I do detect a bit of wanting to please W..... But I do admire you wanting to try to keep th connection between her and the kids. It that is not fully on you, although you should not hinder it, of course.
Painter made an excellent suggestion. Video chatting works on their level. They can put the voice to the face and interact.
Like I had said, when my D9 is occupied, she rarely "misses" the other parent anymore. She engaged in that part of her life. Which is healthy. Your kids are in school with their peers and pretty occupied.
Just like us. When we GAL we don't think of those we miss as much. However, it doesn't mean we forget them or don't love them.