There are two ways to get her an open work permit:
1. At the Port of Entry - (dependent upon getting TRVs) - upon entry at Canada Border Services - you can ask for an open work permit for her which is dependent on your WP NOC category. Right now, only wives of holders of WP with NOC O, A, and B categories are eligible for applying for an SOWP. Faster way.
2. After getting your WP - she then applies for an OWP using details (NOC category) of your WP.
- takes some time, as it is dependent on getting you a WP first. Note here - she is the one who will file the application - not you in behalf of her.
In our experience, it is faster to get the OWP here in Canada. My wife had a TRV only and we did not apply at the POE. After arriving, we applied online for her SOWP and they sent it via mail.