find solutions for their properties through wholesaling.

It's more predatory than solution driven.

If we can't find a solution, I think she will be OK with me adding her property under my own account, and then me paying her out monthly.

You'll save thousands (maybe tens of thousands) and a lot of stress if you educate yourself in advance.

It was a nightmare for us and stressful

Some lenders offer creative solutions, like a cross-collateralized loan, where they use your existing equity as security without refinancing the duplex.Another idea is partnering with private lenders or exploring a second-position mortgage, depending on your lender's terms.

Quote from @Mohit Gupta: @Nick Brown, @Gaby Liu - I just ran into this and would love to know if y'all were able to find a solution! 

I am not exactly sure if calculations are accurate and feel stuck with this decision, I would appreciate if someone could offer an advice or potential solution?

The easiest solution is typically keeping water away from the wall. 

With the property needing lots of work, I provided a solution to the owner.