My H father also died and quickly a few months back. H had just moved back in when we had the diagnosis. I supported H and his family and my family 100 %.
Hs dad died. H moved back out of our house 2 weeks later. Friends were concerned that his grief for Dad was over shadowing his feelings for me. He says not.
End of the day my h said that what I did to him with A was 10 times greater than the grief of losing his father. Sad.
If your W is not supporting , I would say that is a sign that her head is in a fog.
If you were confident in your feelings about being seperated you would get involved. You would keep your distance only if you were risking another relationship or your head just is not screwed on properly.
It is her childrens grandfather. She should be very concerned. Selfish is all i can say