Small village - Loire Valley

I'll highly recommend Azay-le-Rideau. It is about half an hour southwest of Tours, and fits your mother's description to a T. It is a small village with plenty of still-standing historic architecture, a Saturday market, a helpful TI office, and a chateau of its own. There are several gourmet restaurants in town as well as more casual places to eat. When we were there we encountered mostly French people, some tourists from other parts of Europe such as Germany, and zero Americans or other English speakers.

Hotel Biencourt is very charming, located on a very old pedestrian street (but you're allowed to pull your car in to load & unload). The innkeepers are the nicest people you'd ever want to meet. The breakfast buffet is delicious and there's an interior courtyard where you can sit in nice weather. The building is converted from a girls' school dating from the Napoleonic era, with a painting of the teachers on the wall.

From Azay-le-Rideau it's a straight shot (as in, you really can't get lost) to Chinon, which is surrounded by vineyards and has nice shops selling local wines. It also has the restored fortress which is more interesting to visit that some of the other chateaux in the region, given its connections to Joan of Arc, Eleanor of Aquitaine, and the Knights Templar. The RS guide to France describes a self-guided walking tour of the old town in Chinon.

You could either rent a car out of Paris or else take the train to Tours and rent there. If leaving from Paris, Orly airport is near the Autoroute you will take toward Tours.

Amboise is much more touristy, as is the entire northeastern end of the Cher/Loire region, because it's within day trip distance of Paris.

I second the recommendation for Azay-le-Rideau. I stayed there and really enjoyed it. It was very well located for visits to the chateaux, especially those in the western part of the valley.

Chinon is also a smaller town (@7000 pop.) with a quaint old town area so would meet her 'feels' French requirement and may be a little more convenient to visit the vineyards. The wines of the area are predominantly reds so she should be fine with that.

Amboise is very nice and popular with a lot of the posters here. It's a bit larger but still a small town (@13000 pop.) with a quaint, French feeling old town area.

All three have chateaux right there that you can visit and Amboise also has Clos Luce, Da Vinci's last home.

I suggest Loches. It is in the southern part of Touraine and an easy drive to the chateaux. The city is small and so, so French. The centre ville is amazing.

Chinon came to mind for me. I'm a little worried that the best parts are on a slope, which could be a problem for your mother. It felt very old compared to most of the Loire, but not necessarily old in a charming way. I'd be more likely to describe it as authentic.

Amboise is a nice town. I was glad I chose it as a base. Again I'm not sure it has the quintessential charm she may be thinking of.

Unfortunately Azay had scaffolding when I was there so I skipped it on my trip.

We really enjoyed Chinon. It’s not far from Azay Le Rideau (a nice chateau), is on the river, and has ties to the knights templar. We did enjoy Amboise and it isn’t that far from Chenonceaux and its chateau. I can’t speak to the vineyards since we didn’t visit any on that trip.

I recall than Chinon has an elevator for pedestrians to get up to the fortress ruins. Chinon has lots of restaurants. And a Homer Simpson like nuclear plant that you can actually drive by, not like in the U.S.! Make sure your mother will accept a postwar stone city, and doesn't think she's going to a wooden village like Band of Brothers.

Note than many of these recommendations are to the West of Tours. That makes it a longer drive to the famous Chateaux to the East. August is very hot, and also European vacation season. Reserve ahead, and consider ventilation or air conditioning if your mother is sensitive to heat. We stayed in a renovated chateau near Chinon, I think called Château de Marçay. What our host Rick calls a "worthwhile splurge." We signed out a stand-fan from the front desk. Investigate Son et Lumiere in advance if you want to see them, since they tend to sell out. Azay is a very pretty town.

Thank you all so much for your help! We have decided to go with the Chinon and Azay, since they sound wonderful and are so close.