The medical expense tax credit is a non-refundable tax credit that you can use to reduce the tax that you paid or may have to pay. Therefore any increase will be applicable if your partner had available income tax taxes payable to offset against the medical tax credit. You will not create an increase in refund it will reduce the amount you pay in taxes.

https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/rc4065/medical-expe...