PumpkinPie

Well you do sound like a very supportive and patient husband! She's very lucky!
I can totally relate to your wife. I know it's not the exact same scenario but I'm from the US and moved to Ireland when I married my husband who is Irish. I've been here almost 2 years and speak the same language here and I STILL get homesick. Although everyone speaks English over here and it's just right across the pond, it is still a very different culture at the end of the day. It was hard making new friends, most of them were through my husband until I started working and socializing in that way.
No one gets the silly things we do in America unless you grew up there and it just may come across as moronic lol. Like why we have to have a gallon of milk instead of 2 liters; Why we drive on the other side of the road (the right side ); why we celebrate weird holidays like Thanksgiving and always say 'Dude' or 'Duh'. However, I also found Ireland odd too because couldn't understand the Irish accent for the first few months living here, I constantly had to ask people to slow down. The food isn't the same, I really missed variety and selection I had at grocery stores back home. And I also had to relearn everything, such as how the banks here work, how the taxes work, the government, how you have to pay for grocery bags and bag your own groceries, etc. She may find it a bit weird compared to how things work in China. (It's ok if she prefers how things are in China to America, keep that in mind.)
Also, I still get excited when I meet other Americans over here, but if they're here as a student, I can see where she's coming from. When she says that foreign exchange students are 'egocentric' it may be her way of not being able to relate because although they are both from the same background, they came to the US for 2 very different reasons. As for watching TV in Chinese subtitles, again it's not the same but when I watch American shows, it makes me feel like I'm back home (thank god for Youtube ) So maybe it's her way of receiving communication in her native language because she misses it? I've met a few people from other countries that like to use their native language frequently so they don't forget it. My friend from Czech has that issue sometimes.
Anyway, just be very supportive of her and try to talk about China often so she doesn't feel like you're forgetting where she came from. America is a melting pot full of different cultures and her contribution to it may just be what will help her adjust. And remember, liking western culture without living here is not always the same when you actually move here. Sometimes the grass isn't always greener on the other side and perhaps it's not where she wants to be forever. Living the 'American dream' isn't for everyone and I'm sad if that's the case for you and her. Hope it all works out, good luck!