I agree that Shanghai doesn’t have much going for it if you are not in it for the nightlife. It’s a world-class city, and if you’ve been to plenty of those, it doesn’t seem particularly special. Beijing is amazing, but will be crazy, insane cold during that period. Chengdu will be chilly and drizzly, but at least bearable. Yangshuo is beautiful, but the weather may or may not cooperate. Last time I was there in Feb is was unbearably cold and buildings in the area are poorly heated. But the year before that, it was sunny and warm. Hainan is not worth it- there are better beaches just about anywhere else.
I second the idea of a Yunnan trip. Yunnan will be sunny and reasonably warm, and it’s one of the most friendly and relaxed places in China to travel (well, as long as you don’t need a cab in Kunming.) It should be a cheap and easy flight.
I’d skip Kunming, which is fun but doesn’t have a lot to offer a visitor. Dali and Lijiang are fun old towns with more than a hint of Disneyland to them. They are fun picture-perfect places to explore, watch the madness of Chinese local tourism, buy souvenirs and sample local foods. Both towns resemble what the fantasy China in your mind might look like.
For a more authentic experience, there are tons of opportunities to hike or bike to local villages. Yunnan has a high concentration of minorities, and is one fo the few places in China where traditional lifestyles are winning out agains the bland corporate white-tile-and-KTV sameness that is steamrolling through China as sure as McDonalds and WalMart generalized America. It’s one of the few accessible places where you can see people in traditional costume going about their everyday business.
Hiking Tiger Leaping gorge is totally worth it if you have any interest in the outdoors. Beautiful! All of this should be more than enough for a week.
If you are looking for hostel-level accommodations, the Hump in Kunming, Mama Naxi in Lijiang and of course Jane’s Guest house on the way to the gorge are the only places to go. All three are friendly, informative, full of interesting people to meet, and will do their damndest to make your trip a ton of fun. All are comfortable and have private rooms, and I would choose them in a second over the sterile cookie-cutter white tile hotels that dot China.
If she decides on Beijing, I can also recommend a pretty special hotel. Let me know.
If there is any way she can get used to the idea of travelling solo, I would highly recommend that. China’s organized tour industry is still monopolized by the state tourism companies, which appear to be stuck a couple decades back. Even places that look independent are actually just fronts for the three state tourism agencies. And that means you’ll get lots of boring commentary about the size of every room and questionable historical information, hours upon hours of enforced shopping trips to state-owned souvenir emporiums (disguised on your iteniery as a “trip to a silk factory” or “visit to stone carver’s workshop”), bland institutional food served in cavernous dining halls that deal only in package tours, and large, empty government owned hotels with crystal chandeliers in the lobby and no hot water in the rooms.
I know going solo is intimidating with the language barrier, but the tourist trail (especially in places like Yunnan) is well, well travelled and geared towards solo travel. You’ll meet tons of people in the “go to” hostels to explore during the day with, and your hostels will be absolutely ready to help you arrange transportation, write down the names of locations to show taxi drivers, etc. They have ample experience with what Western travelers need, and can give it to you.
If you must take a tour, go to Tibet, which is only really accessible on a tour.