Rereading my post I may have made my primary residence situation hard to understand.

Edit- rereading your initial post, I assume your platform would have an app or a website that the property manager/owner would use and the tenant only uses texts?

@Remington Lyman reread this and my brain went to renting out a room, not house hacking.

I've been re-reading the BiggerPockets book The House Hacking Strategy by Craig Curelop, and the numbers are eye-opening.🔥 Why Co-Living & House Hacking Work So Well Together✅ Higher Rental Income Per Unit – Renting by the room typically beats traditional rental rates.✅ Lower Vacancy Risk – Losing one tenant doesn’t mean losing all your cash flow.✅ More Affordable for Renters – Competitive pricing attracts a steady stream of demand.✅ Built-In Community = Lower Turnover – Tenants stay longer when they feel connected.✅ Allows You to House Hack a Single-Family Home – No need to compete for pricey duplexes and triplexes!

To learn how to do the analysis, I highly recommend you read, highlight, and reread two books:   both by Brandon Turner, first is Rental Property Investing which talks about finding, financing and everything to screening tenants for rental properties and the second book is  volume One of the Multi Family  Millionaire.  

Do you still have a copy of their report to reread?

I'd reread the lease.

I know you reading comprehension is incredibly poor, so just keep re-reading the bolded sentence over and over again until it makes sense to you or ask someone with better reading comprehension ability to explain it to you.   

Upon rereading the thread, it isn’t clear why OP needs to verify granddaughter’s claim, track down the notary, etc.

I’ve re-read it multiple times since.It’s easily in my top 3 books of all time for financial education.