How to form possessive for a list of people? "(Jane Doe and I)'s" [duplicate]

I'm writing a sentence, and I'm not sure if it's grammatically correct.

Here are my partner, Jane Doe, and I's completed assignment.

Would this be alright? I never know how to properly use possessives when I'm including myself and someone else.

Also, in case you didn't see my comment below, I need to include my partner's name. It can't just be "me and my partner's completed assignment". Otherwise, I wouldn't have an issue.

Without more substantial rephrasing, it will sound strange even if it is technically correct.

It would be more natural if you simply drop the use of the possessive:

Here is the completed assignment of my partner, Jane Doe, and me.