They call this RCFE (Residential Care For The Elderly) or Board and Care in CA.It is not medical and you can do this in a single family home.  

(walkable distance adjacent to my parent's property)I want to help my elderly dad paying off the bank-owned land(2nd property), fixing, flipping and renting out old falling down 12x60 singlewide trailer as my first time home flipper/landlord.

@Nick Elder I think that the lease of the 3rd room would have to be between the owner and the tenant.

You are wanting seller financing (taxes aside their elderly do what good is money to them if they’re dead??).

Ill make this as short as possible.....I have an elder family member who does not want to own a house, she wants to rent from my wife and I as we are trying to grow our portfolio.I currently do not have enough $$ to just go out and do traditional financing to place her.However, she was recently approved for an FHA loan.

Purchase price: $95,000 Cash invested: $55,000 Sale price: $215,000 Pre-foreclose, elderly person living in the house in a extreme poor condition , we offer alternative for his living , We help the owner with a better place to live , we help the bank by giving them Money for a deal that will take a lot of money to be back and functional , we hale the neighborhood by eliminating a house that was a close to tear down and in a bad shape , What made you interested in investing in this type of deal?

And so on...I live in an area with lots of retirees and homes that are fitted for the elderly sell much faster. 

Avoid section 8 tenants unless they are elderly and sober.

When a tenant can't pay rent on their own and relies on Section 8, mom, or their elderly uncle, that's a red flag that other issues will pop up.

How would go about finding elderly to fill occupancy for a small independent living facility?