What is the best discreet camera to watch elderly parent living at home while you are not there?

I used the Blink cameras when my husband was completely bedridden in our living room, so I could check on him when I had to leave the house for any reason. I could access the camera in the living room on my phone and make sure that he was ok. I have the older models where you could only hear the sound in the room where camera was, but they now make them with 2 way talk which is even better, as you can talk to your loved one if needed.
They're fairly inexpensive, and require no monthly fee, and the picture quality is pretty decent too. You do however need WIFI in the house to set them up.
Good luck in finding what works best for you.

I have an Arlo in my Mother's apartment..one in living room one in bedroom. Works great..allows you to see in the dark as well. No monthly fees once purchased..unless you want it to record, etc. One she has requires wifi but I think newer ones do not.

Any of the cameras would work well. Find one in your price range with the features you want or need.
People forget cameras are there so it almost does not matter how large or small they are.