Now, she is in grade 2 here at Canada. Although she doesn't like Canada either, but she could find a lot of Chinese friends here (since I live in an apartment in downtown) as well as some foreign kids.
You should worry about your money, job, education, etc, but never worry about your child. S/he will be fine.
However, the education system is defferent than China. No one will tell you or your kid that s/he need to work hard to catch up with the others, but the teacher does have a record sheet for each student. As a parent, you'll have to push your kid to read/write English, learn math, etc. It's your responsiblity, more than China.
For English, I always said to my wife why I could not find any improvement on my daughter's English during the first months. But 3 months later, I found she could understand and speak a lot. Now, she could sometimes correct my pronunciation.
In one word, don't worry about your kid! And, good luck.