Successfully renegotiating an inherited tenant lease?

[Christian Longacre]

In a recently purchased property, I inherited a good tenant who is 1 year into a 5-year lease.  She's related to the previous owner, and the monthly rent is probably $200 below-market.  I like her as a tenant, and she really likes her apartment and the location -- she's retired and says she would like to stay for many years.

In a recent conversation, she mentioned that the old single-pane windows and doors are drafty in the winter (not uninhabitable, just drafty).  Normally I think that's a renovation I would do in-between tenants, and my understanding is that she agreed to lease the property in its current condition.  This is truly a "discomfort" issue and not related to safety or habitability.

I think there's an opportunity to renegotiate the monthly rent in exchange for making the upgrades that she wants, and it's an upgrade that I wanted to do anyway.  Does anyone have advice on renegotiating a lease that could help with my situation?