This is make-believe time for me since I too live at home with my parents.
My mum has a bad back and wouldn’t be able to sleep comfortably. I would make sure to set the couch up for her, which is where she prefers to sleep. She also consumes mass quantities of tea. That would be the number one item on my grocery list prior to my parents’ arrival. There is no way my mum could go two weeks without her fix.
I would also check that my medicine cabinet and emergency kits are well stocked (particularly concerning pain medication, stomach relief medicine, and bandages.) Even if my parents remember to bring over-the-counter stuff along with their daily medication, it’s good to have back up just in case.
I’d also make sure the guest bathroom had unscented products because just about everything breaks my mother out into hives or gives her a headache.
Other than those things, I would wonder what the hell I would do to entertain them for two weeks. Surely they know by now how extraordinarily dull I am.