Ya someone just asked this same question in Korean thread. Here was my response.
Basically there are only 2 ways she can work
1. Get the Korean equivalent of the working holiday visa (IEC program only available to people under 30, and usually spots are filled up super quick), see here: http://www.canadainternational.gc.ca/korea-coree/experience_canada_experience/index.aspx )
2. Find an employer willing to go through LMO process successfully, after which she could apply for closed-work permit to work for that company. http://www.cic.gc.ca/english/work/employers/lmo-basics.asp
As zardoz said, there is no other way she can legally work. She would need to apply for her PR, and then after 10-12 months she could most likely work, but not before that.