@Peter Kopchik If you know the people just go knock on their door and ask.
You can work with the seller to carry a note for your which you can pay back over a period of time. This can put her in a tax advantageous position (consult with your CPA) while deferring/avoiding taxes (depending on how you structure the deal).
Would suggest consulting a GC and getting bids for the rehab before proceeding forward. Older properties can be a PITA to rehab.