MagicDragon

Thanks, we got it worked out.

I think this section is very badly written. We all have busy lives, for many in the process English is not the native language, and we don't need mindless bureaucrats obfuscating the process. The sentence "The filing fee for form I-485 is $1,140." is definitive. I shouldn't have to read any further. If there is a calculation that needs performed that should be introduced and then explained that there is a basic fee, a biometrics fee, and other fees as needed. If there is a table, then the sentence should say, "refer to the table below for the fees you will need to pay." Returning a payment without any explanation of what they expected is also incomprehensibly stupidly boneheaded f'ng nonsense. Sorry, as nice a person as I try to be most of the time, this type of intentionally unhelpful mindless drone people is one of the few things in life that rub me the wrong way.

You can check the CIC website for visa requirements - http://www.cic.gc.ca/english/visit/visas.asp
 
As SusieQQQ mentioned, green card holders can visit Canada without a visa - an eTA is required if flying, though. Until your wife receives her green card, she'll need a visa - details at http://www.cic.gc.ca/english/visit/apply-how.asp.

With the exception of Canada and Mexico and some Caribbean islands where having a green card will exempt you from visas, and the case of transit visas only in the U.K., all other countries that I am aware of base visa requirements solely on passport and not country of residence. If a Chinese passport holder needs a visa, she will need a visa. 
 
If she doesn't have a green card yet I'm not sure if she can visit Canada visa free, after all AOS doesn't guarantee a green card at the end of it.