One thing to consider, rents should also gradually increase every year so theoretically, in 3-5 years, the increased rents will hopefully offset some of that increased interest payment.

A lot of people have had success gradually building up their portfolio of SFH or smaller multifamily rental properties and then they level up into larger assets - it's a great path and has worked for many, but it's definitely not the only path.

Gradually increase rents if it is a large increase that is needed.

Another option is to (gradually) raise the rent on your month to month tenants.

If you don't have extra to fix it up right away, you may need to live in it as is and gradually fix it up. 

Would you just keep it cause she's always paid on time, go up gradually, or jump it to market or?

If you still have limited data try gradually expanding your search farther out (i.e from .25 miles radius to .50). 

He came up a few weekends ago with my sister to check out the progress and said, compared to what he had seen, he wouldn't be scared to ask $800 and take it down gradually from there until it's rented... sounds like a decent plan. 

Inventory as a result has made some gradual improvement. 

(During the summer) We originally rented by the room and then gradually converted most to single leases per unit.