Refi'ing into a 15yr loan is likely to both increase your effective rate and crimp your future buying power by increasing your DTI. 

In truth you don't have a lot of power over when and if she pays, but you can and should use the power you have.We have this clause in our agreement and we talk about it before they move in so that they are clear who the primary is and what that means. 

This is what makes it so powerful.

It's an incredibly powerful form of leverage.

The power of REI in todays market is delayed gratification  combines with the tax benefits the following year. 

And if a family office will demand more power and ability to change things to their own liking.

Consider working with a lender to get pre-approved for financing, as that will give you an idea of your buying power.

Shortly after they were off to the races (the power of the first deal).

We also do a walk through, set expectations for maintenance, filters, lawn, garbage and go over the function of GFCI's, shut off locations (water, power, gas).

Cash flow is not its main power.