I feel that something like backblaze personal backup is a good option. It's great if they have some local backup drive for this additionally (3-2-1), but it's pretty bulletproof to have unlimited online backup storage for your parent's home PC. From accidentally deleting a file, to a house fire.. everything is backed up outside the home. Just have it back up from the time they go to bed normally, and the time they wake up, and they won't need to do anything or worry about it. Plus, it's affordable af for what it is. My 2 cents.