Your question is a little confusing...
If your spouse is the applicant and she is applying outside of Canada then your spouse does not need to be in Canada at all. The only restriction is on sponsors leaving Canada if they are not themselves citizens.
Unless your question is about your spouse re-entering Canada before the process is completed, in which case it depends on whether she is from a visa exempt country or has a temporary visa of some kind, and being able to prove that she is intendnig to leave again if the application is not approved. If your spouse is in Canada and applying from outside, she must be able to leave Canada because she may need to leave for an interview in the country she is applying through...
As I said, your question is a little vague. If you put more information maybe someone can help you more.