I'm sorry for your difficult situation.

I was saved in 1980 at the age of 21. My first wife had two stillborn children. She passed away due to complications from kidney disease when she was 30. That was 25 years ago.

There are obviously no easy answers as to why God does what He does or why He allows what He allows. I think sometimes God has believers go through trials or tragedies to either make them grow or to be a model of remaining faithful despite tragedy.