Hi @FrankMurphy
You certainly can add your wife to your account, but to ensure that you both can have meetings longer than 40 minutes, you will need to purchase an additional license on your account, that you will assign to her. Moving her on to your account won't save any money (as you will still be paying for 2 licenses), but it will simply your billing.
Here is an article about how to invite her to your account: https://support.zoom.us/hc/en-us/articles/360028938451-Adding-existing-users-to-a-paid-account
Just a heads up though, her meeting reports on her account will not transfer to your account, so if she uses any reporting, she should be sure to download those before accepting your invitation.
Hope that helps and please make sure to mark the solution as accepted if this information is what you needed.