Sal,
Your grief and load of waiting is shared and lifted up to our Heavenly Father by us all.
Your heart is trad. And this is one forum where we can come about anything and ask for prayers from brothers and sisters around the world. Many, many come here, read, pray and never post.
The good news about your Sister-in-law is that even Death is God's perfect healing. She will be standing before Christ soon, made perfect in Body, Mind and Soul but the blood of Jesus.
Strength for you to be that pillar for your wife. May God's Grace wrap around you all in this trying time.
Keep the Son in your eyes!