My condolences on the passing of your FIL. He suffered quite a bit towards the end and he's now at peace and suffering no more. I'm glad that you and the girls went to visit him months ago.
I think you are very wise in passing on the "invitation" to attend service. If your xw opts to share info about it, thank her, but then let it go. Your xw is going to be a mess for a while, but we shall see if this gives her "pause" for thought about what she's done and continues to do.
Again, I am very sorry for your loss.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
