With the delayed settlement  agreement, would give you time to clean the house up a little and market the house using the short date sale method. 

However, these were done in the NYC metro area long ago which I believe is too difficult for a beginner to start in. 

Our goal is to start buying MF within the next year to two years.

That wil get you started.

I enjoy visuals and management, which got me started on Airbnb.

This sounds great, I just started investing in the US (and a few challenges have already popped up), so would love to meet and hear from you @Marco Santarelli and @Cal Ewing and others who are already active in that market.

I started out on Stessa when it was free.

Hello everyone, With deciding to start in real estate, my main goal is to create enough equity in the properties I obtain to build a house and buy land  (10-12) years down the line.Though the market always changes, I figured with investing into highly appreciating markets now, the properties I buy will accumulate the equity needed to be able to sell in the future which in turn will lead to the income needed to build and buy land. 

I definitely recommend checking some of the real estate meetups in the area (there are plenty to choose from) to start getting connected with people in similar spots and to find resources to help.Happy to answer any questions you might have.

I, personally, would consider any other option, including bankruptcy for your sister if she really has that much debt that she can't pay, rather than ask my nephew to give that much equity away and start over smaller with a much higher rate.