She's the only medical doctor for miles. Good luck replacing her. (Hypothetically anyway. Its an option, but my Sister is more realistically looking to live closer to friends / family and is probably going to turn down such offers)
Overall, small town doctor is a pretty good position to be in. There's lot of other ways of living rather than FANG-style tech. High-quality doctors and/or nurse practitioners make big money in small-towns.
If you're the only doctor (or one of ~5ish nurse practitioners trained for emergency care) in a 10-mile area, you're going to be a highly-valued member of that town. Period. Its not even to "cure" all diseases, but you need a highly-trained medical professional to know if the ~2-hour journey to the big city hospital 100 miles away is worthwhile.
Ex: You may have to travel 100+ miles to get to the nearest MRI or CAT-scan machine. The local doctor will provide medical advice for whether or not the trip is worthwhile based on the diagnosis of less-sophisticated tools.
--------
The main problem with becoming "THE Doctor" of a small town is that you have to move away from your social networks. IE: My sister would have to live very far away from the rest of her brothers / sisters / parents, and that's a tough sell from a social standpoint.