I have lost both parents and my entire mother's side of the family, at 40 yrs. old, and responsible for the burial 4 of them... it is the nicest thing you can do for your family. It will save a ton of "wondering", "did we do the right thing?", "is that what he/ she would have really wanted?" It will also settle any disputes that may arise as well. Bravo to you and although they might not be keen on knowing/ thinking about it right now, they will be soooo thankful when the time comes :)