Her credit score differs from yours still. When you say you use the same credit card, it has to be set up in such a way that it can also go towards her credit score. Are you co-applicants/co-borrowers? That’s the only way it can go to both people’s credit scores. An authorized user or additional card holder does not get it towards their credit score.

We are co- applicants 

I would suggest reviewing her credit score vs yours with both Equifax and Transunion then to see the differences and if it’s missing.

There are other options with Koodo, such as going prepaid, or you can ask about the Koodo spending limit programme or you can open a line on your own account, although you’d show up as the owner while she could be an authorized user.