After early stages, I'd be wary of her continuing to cook. It's not just about leaving the stove on. The judgment also goes, so they may not realize how hot the food is and burn themselves. They may not realize how something might cut you and bleed and they may also not be able to recall how to call for help or exit the building in case of fire. I recall how I turned off my LO's stove on the circuit breaker. (Washer and dryer too.) And took her her meals to her everyday. But, it became apparent, that it's not just the short term memory at some point. It's a loss of judgment too, that can cause them risk of harm.
There is a product called Smarturns. It is attached to the stove and your Mom would not notice any change, while you get notification message on your mobile phone everytime she turns on/off the stove. It does not turn off the stove though. You can search the keyword "Smarturns" and find out more.
I just unplugged the stove and told my mom that it didn't work. I was so worried, after seeing her burn a pot of soup, that she would burn her house down.
I have been thinking that way. Countertop oven could be in a smart outlet I think. Because it does not require 220. She can think her way through most cooking tasks but can't be trusted to not forget. Future will require more supervision. She is 92.
I'm thinking that if you need to go to such extremes to limit her cooking she shouldn't be cooking at all. If you feel she has the capacity to fix herself simple meals then invest in a good counter top oven, an induction hotplate and an electric kettle for hot water which all should have built in timers/shut offs as safety features.
Nothing that I know of. You'd have to find an electrician/techno guy to do some wiring, relays, and solenoids, set up wireless communication etc. pretty big bucks.
https://iguardfire.com/