I want to buy the property on terms and demo, build a new house.I want to structure an owner finance deal with him where I either pay him interest only on the lot or no payments for 18 months (or until the new house completes and sells whichever is earlier). 

I will assume his loan and he pays me his mortgage, plus a little extra.

They will supposedly first pay you back your initial earnest money with interest within four weeks of signing their NEW RELEASE AGREEMENTS as a show of good faith if you get in touch with their attorney (send me a private message so I can send you instructions to get in contact with their attorney), and then the remaining outstanding deposit with interest within two months after that. 

The thing is, she has until the 2nd of July to pay her back taxes, and if she is unable to pay by July 2nd, she will have to file for tax bankruptcy.

You can do a ‘cash out’ refinance on the rental home as a permanent fixed 20-25-30 year loan to pay off the Heloc on the primary and most likely the equity line on the primary permits a ‘re-draw’ to utilize again. 

She'd have to invest some money to create this set-up. 3) Selling doesn't make a lot of sense, because in this market, she'd end up paying the same for a small place, condo, with less flexibility. 

They would work enough to pay rent but attend school enough to graduate. 

Unless you start with a property that has that infrastructure already in place, where you will then pay a premium for that. 

Is there such a thing as a service that you can pay an experienced real estate investor to find properties for you? 

They stay in business by charging premiums and not paying claims, or challenging them and not paying them in full.