Sensitive Situation with Seller. How to Handle

[William Coet]

Hello,
The situation:  Edit: She is the homeowner, not yet a seller.  A woman in her 70s lives in a home and has no children and is a hoarder.  The home is in very poor condition and has been neglected for decades.   She is very eccentric and sometimes irritable with an erratic personality.  She is likely not in a good financial situation.  Nonetheless, she likely does not want to leave the home.  
I am seeking advice on how to navigate this situation because I would like to purchase the home.  I can offer her lifetime use, or perhaps another similar arrangement so that she does not feel threatened but she could also benefit from having the income from a sale.
Any thoughts on how to find a mutually beneficial arrangement would be very much appreciated.
Thank you