Solution is earning with you own head instead of waiting when your family member will die.
You will get the bitcoins only if you will know private key or seed words.
That is a little harsh. He is just asking.
You need something like a clue maybe. That is one hell of a hard problem. Now that I thought of it maybe I need to leave some notes for my wife in case that happen. Thank you for reminding that.
I dont think there is a way and that is also one more reason why bitcoin will be rare in the future.