My mom actually isn’t that old (only 60) but she asked me to ask you all to recommend an “old lady snowblower” for her.
She wants to be able to clear her front walk, which gets high drifts, and also clear paths around the back yard for the dogs.
We can get some pretty tall snow here, a foot or more. But she also can use the machine at her leisure - that is, no need to hurry up and get the walk cleared by 9 AM or anything.
Easy start is important. She does have access to electrical in the front and back yards, if an electric model is good.
She’s short, just 5’2", so a nice compact one would be good.
If she has something that’s reliable and easy to use, then money is no object.
I don’t have any recommendations, but we’ve used a small electric Craftsman model for years. It’s much lighter than a gas-powered model. OTOH, it’s much smaller (I think it’s about 14") and slower. On the third hand, if your mother can work “at her leisure” those aren’t negatives.
Your requirements are somewhat incompatible. Easy to use electric paddle type snow equipment is not suitable for 12" snows. And since your mom is not prepared to run out at every 4", I would say an auger type is required. Usually, those are much bigger and heavier. Of course, you could find an auger type with electric start and self propelled that would make it rather more user friendly. If they exist, an electric auger type that advertises the capability of handling 12" would be nice.
All this begs the question of how she has removed the snow in past years. Does she really need a snow blower? Could a small electric paddle type handle 80% of the snowfalls while the good son takes care of the 20%?
Bottom line guess: If she is fit, I would go with the smallest width auger type with electric start and self propulsion. Move up in width depending on your estimate of fitness. (A larger self-propelled machine still needs to be moved about some with that function disabled while storing and retrieving.)
I’ve been using a Toro electric snow blower for several years and it works just fine.
I’m not a little old lady but I am a scrawny old man with zero mechanical aptitude. The guys in the neighborhood poked a lot of fun at my “cute” little snow blower when I first got it but they didn’t have much to say after the first time it happened that my walks were done and I went over to watch them yank their crank and diddle their carburetor trying to get started.