My gf (who's a local) was like this when we first started dating and I was in the same boat as you.
Not only did I bring her along to 100% English speaking groups, but we would also only talk about cycling. Which she has no interest in. I made this mistake very early on and it resulted in a long time where I would show up to social gatherings alone.
It took a lot of time for her to ease into the group. I started off with double dating with a foreign couple (one of which was pretty fluent in Chinese and the other understood a little). She slowly started feeling comfortable around English speakers and was willing to come out for a drink or a meal with my friends.
You also have to put yourself in her shoes. If you were going to social gatherings where you couldn't understand a single word the people were talking about, you'd refrain from going in the future too, right? I know Taiwan may be an exception because there's gotta be that one person in the group that understands English, but for arguments sake, let's say there isn't. A few times I went out to meet her friends and even though they were speaking Chinese, I couldn't understand the higher level of vocabulary used and was completely lost. Another time I met with the gf and her co-workers and they were jibber jabbering away about work things and I had no way to relate.
If she's sweet and a good girl, it's worth trying, right? If she's finding excuses, throwing tantrums, and getting angry for no reason when you invite her out, it's time to re-evaluate again and see if you guys can continue. My advice is, to find people that speak both fluent English and Chinese. Like Chris said, start small. Meet with one friend, then meet his/her significant other and so on and so forth. If it's tough finding new friends, once your gf is warmed up to one of your friends, have them invite their local friends/gf/bf along. Letting her know that so and so will be there, so she will have someone to chat with, will ease her concerns.
It may take some time, but if you see a future with her, you gotta be a little patient. 6-8 months is always a crucial part of a blossoming relationship!