Lease question: family member needs to stay for a few months

[Ryan Miller]

I have a tenant that’s been renting one of my properties for years. He asked me today if his sister can stay with him for the next 4 or 5 months. I have no problem with his sister staying with him but wondering how I should structure the lease.

Should I create a new lease for both of them, an additional lease for her, an addendum or anything else I missing?

Thank you for the help!