Shared calendar goes to wrong account

I'm trying to add my partner's calendar to mine.  I myself was using the Windows calendar as my email is with gmail, not outlook.  I don't have 365.  Previously, she sent me an invitation and I successfully added her calendar to mine.  Now that I have migrated to New Outlook only my Google calendar that was on the Windows calendar has shown up.  I went back to her computer and shared her calendar with both my Google account and my Microsoft account but it starts a completely different Outlook calendar which does not have mine on it.  How do I change that or merge the two?