Annecy

I've only driven through Annecy, so can't help with the town itself. But a great daytrip from there would be to Chamonix for the cable car up to l'Aiguille du Midi, and some alpine hiking.

Annecy is lovely, it was one of my favorite towns in France. I only stayed for 2 nights and would have been happy with a few more. Since I was only there for 2 nights I didn't day trip to anywhere else, but there are plenty of good choices if you're staying there longer. If you have a car it's easier to get to other places in the Alpine area such as Chamonix, Aix-les-Bains, Chambery, Albertville, etc. If you want a bigger city change of pace you could day trip to Lyon or Geneva. Annecy is aesthetically pleasing, being situated on the lake and with the canals running through the town, and it's very photogenic (which was what I was so impressed with), and it also has a wonderful weekly market along the canals. There are walking/biking trails around the lake and boats that take you around the lake to the smaller villages.

Your daughter probably already knows this, but you'll want an air-conditioned apartment; Annecy can get quite hot in the summer.

It's a very pretty town, and the setting on the lake is great, but Annecy was absolutely overrun when I was there in late June 2017. It wouldn't be my choice for a month, but then I prefer larger cities if I'm staying more than just a few days, and I don't travel by car. I'm sure there are lots of good side-trips. One that was recommended to me by an internet acquaintance who lives in that part of France was Yvoire, a medieval French town on the south shore of Lake Geneva. Unfortunately, I didn't have time for it. ViaMichelin estimates the driving time from Annecy at about 1 hour.

hey hey don
we stayed 6 nights in annecy late september 2019 in a 2 bedroom apartment. we loved annecy, it's gorgeous views of the mountains, terrace/balcony to have our coffee, wine and appetizers, washing machine, kitchenette, close to town center, the lake and canals, shops, cafes, restaurants, walking thru the village where there is market days twice a week. we hired a private taxi tour to take us around the lake thru small villages, stopping for photo shoots, hang gliders soaring right above you, local church that the pope had a service, chateau-de-menthon.com (inspired disney to build sleeping beauty's castle), cows in the green pastures wearing cowbells, went to a working dairy farm for a pre fixed lunch of cheese made there, boat tours on the lake, sit and relax, roam the town, eat fondue and crepes. frenchmoments.eu (retour des alpages) annual festival of animals coming down from pastures with cattle parade thru streets with food, crafts music, dancing if you are there (first week of october) en.lac-annecy.com, annecycitytour.fr
will you be spending the whole month with your daughter? have you found a place to stay, maybe rent a car a few days, look for parking available or how far away, if you are renting car get an IDP from AAA/CAA $25 and 2 passport photos, coincides with your driver's license. look at cities nearby to take the train to, station is closeby. any other questions just ask,

aloha

Aiguille du Midi, Chambéry, Talliores and Val d'Isere are doable day trips from Annecy. You can also visit Lyon, the food capital of FR. You may also consider flying into Lyon since you can fly non-stop to and from a lot of European cities.
In Italy you can take day trips to Courmayeur and Aosta. A good day trip in Switzerland is Chateau de Chillon.

Relatives of mine were in Lyon last year and said they liked it more than Paris.

We love Annecy! We arranged a 6 week home swap there in 2003. We had a beautiful old home right across from the Chateau up high over the old town. We also had a car at our disposal as well. We loved the old town and could walk anywhere in minutes. Great restaurants, wonderful market days, great summer ambience with street performers & live music on many nights. Fete du Lac on August 1 is a tremendous firework and music over the lac. Be sure to buy tickets in advance as it very popular! Lac is awesome for swimming , bike rides, picnics and relaxing. Annecy is a handy base to visit other popular towns in the Haute Savoie. Also an easy trip to Lyon for a big city fix. Summer can be super super hot ....so yes air-conditioning would be awesome to have! Easy also to visit Geneva for a big city or use the airport. Traffic can be quite bad on summer weekends so getting in and out with car can be a hassle and parking is always a premium. We had parking at our house so it wasn't an issue for us but getting in and out could be quite tricky at times. Wonderful towns to visit along Lake Geneva as well (Yvoire). We would go back in a hear beat and have made subsequent quick visits in the years that have passed ... we always make a reason to stop if nearby. I can provide more details about town and other trips we did from there if interested.

There are many, many things to do, but you do need a car to make the most of it. You would run out of public transportation-friendly day trips in a week or so.
Many highlights have been named already, but some are quite far - even Chamonix makes for a long day! I would spend the night.
Thankfully there are many amazing places much closer, within 30 miles I can think of:
- Lake Annecy itself, as mentioned by others
- Lake Bourget near Chambéry : Aix Les Bains is worth a stop, and the Hautecombe Abbey, resting place of the Dukes of Savoy, is very atmospheric
- the drive up Semnoz mountain provides an incredible view of the northern french Alps on a clear day
- the Fier River gorge walkway is a fun thrill and makes for a good cloudy day activity
- there are beautiful hikes in the Aravis mountain range, especially around la Clusaz, and they can be very gentle (e.g. the hike to Chalet du Curé from Aravis pass - excellent view of the Mont Blanc range from there)
The list goes on!

Annecy is lovely. If you know how to sail, you can rent a small sailboat and enjoy the lake. We did that; it's one of our favorite memories. I believe there are boat rides, too. Annecy was great for just relaxing by the lake, enjoying French wine, and yes, we even ate fondue in July. I can't remember that we did much in Annecy except stroll the lanes, enjoy the lake views, drink, and eat. lol. But that was pretty great.

There were definitely boat trips on the lake in 2017. It was a very nice way to spend an hour or two. Previous experience in Switzerland had taught me there's definitely a point of diminishing returns where lake-boat trips are concerned. Multiple short trips (on separate days) are more fun than a long (4- or 6-hour) trip.

I spent 4 nights there in late May a few years ago. Even that time of year it was quite warm. My don’t miss recommendation is to take a long bike trip around the lake (as far as your fitness will allow). You can either pack a picnic lunch or there are some lovely hotels with restaurants you can stop at.
Large boats, each full of hundreds of day-trippers, stop at Annecy around 10 am if memory serves. They swarm the lakefront and old town, then leave around 4-5, so keep this in mind as you make your daily plans.