Take your cues from them. As hard as it is for you to process, it is harder for both of them and feeling they have to put on a brave front, or respond to the continual attention of others is not necessarily helpful as well-meaning as it may be. Don't know the living arrangements, but if appropriate look for chores -- cleaning, cooking, etc. -- you can step in and do without being asked (unless doing those chores are one way either is using to try and distract themselves).