"My wife just got here on a CR-1 visa. How long would it take her to get her green card?"
Normally, the USCIS will send the green card within two to four weeks. So, she should be able to get her green card within that time frame, unless you move to another address. Usually, it will be returned back to the USCIS and you have 60 days to contact them, otherwise, they will destroy her green card and you have to apply for a replacement, which is several hundred dollars. So, make sure you contact the USCIS if you don't receive her green card within two to four weeks upon arrival.