Like they say on the website...you might be confident she will return but you have to convince them.
Three main things they look for:
1. Danger to Canada, health or criminality.
2. Can support herself while here.
3. Will return.
First two are easy to prove. Third one is the tricky one. And unfortunately because of historical patterns the burden of proof might be very high indeed for your situation. I know because my situation was almost the same as yours and we were refused for a temp visa a a year ago.
Things that might help prove she will return:
-property back home
-previous travel to any other countries where she returned
-financial or other obligations that she has to return for
Or go here and read the section starting on page 11...Assessing the application and look at the areas of concern and things to consider.
http://www.cic.gc.ca/english/resources/manuals/op/op11e.pdf