@Kenneth It would be ridiculous to offer a Family plan that grants all family members access to Premium features and then not actually give all of the family members the features we promised. If we, or any company did that, we would not have a business for long.
What you need to do first is add your wife's account as a family member in mSecure's Settings if you haven't done that yet. This will make it so that your wife's account has access to Premium features as long as your Family subscription is active. To do that, follow the instructions here: https://support.msecure.com/en/support/solutions/articles/36000414791-family-subscription-plans
After you have added your wife's account, you'll need to follow the instructions here to set up Cross-Account Sharing: https://support.msecure.com/en/support/solutions/articles/36000318549-sharing-center
Were you able to get your wife added as a family member and set up Cross-Account Sharing Kenneth?
Kenneth