Lots of areas that pencil very well on paper but the quality of renter you will get is going to eat into any profit you may think you are getting.

For flips, ensure the profit margin after all costs is at least 20%-25%.

I have 3 joint venture deals that were presented to me as netting 170% profits in 2 years. 

I used the 75% rule on the income and added it and my DTI without the rental goes from 24% to 38%.Or does it just allow me to just take the net profit of that rental and add it to my rental? 

I would also urge you to make sure you fully understand how they operate , A-Z (from how they make their profit to how many doors they are managing). 

With Amanda Frecks as a partner and a clear plan for strategic improvements, it was the perfect fit for a quick flip and profit.

A good place to start figuring out profit/cash flow is to search the forums for the 4 Square Analysis. 

But you are required to file a Schedule E in the US every year showing the total rents you received, the expenses you had against those  rents and your subsequent profit or loss. 

If she's 70 and still working, my guess is it is not a high paying job and she should have some pension she's also getting.As Kevin mentioned, there are a lot of charitable organizations that will help people out in this situation, especially if they are seniors. 

If anyone does this, theyre likely doing it as a favor and not a for-profit venture.