I don't think I have much more I could help you with-- I applied through Express Entry because I'm qualified for it, and that might not be something that works for you. Your individual details won't really change much about your options, unless you're going to tell me that your gf is also a Canadian citizen, haha. You can PM me on this site if you want, but I'm not an expert, I just happened to be in a similar situation.
She can work up to 20 hours a week off campus if she is on a study permit and provided she is attending school as a full time student. However she will be paying international student fees to study here - which are substantially higher than domestic student fees. Recommend you look into what this will cost her before going down this route. She will need to show a bank balance of at least $25K just to be approved for the study permit (this $25K is to cover her first year tuition and living expenses).
