After your wife lands in Canada as PR, it's better to be full time student or work full time. That will help her to get B1/B2 multiple entry visa. As long as your wife can demostration her tie to Canada such as study and work, she can get the visa.
My wife is full time student and she got the visa. She only got a one-year visa instead of 5-year or 10-year other Canadian PRs have. I guess it's due to the fact I'm US GC holder.