The reason to have comparables is if you are representing someone or perhaps purchasing a house for yourself to live in.

Is there a demand clause where they can call the loans for no reason?

If they want to leave, for any reason, they just have to pretend they can't afford the rent.

Ask questions to find out about their reasons for selling, desired next steps (i.e. relocation, 1031 exchange, etc.), and anything else that is important to them.Ask follow-up questions to dig deeper and learn more (without being too intrusive) then jot down any relevant notes so that you can reference them down the line during your follow-up calls.

Quote from @Jason Burkart: Quote from @Theresa Harris: Whatever you do, I'd keep it in your name if you are the one paying for it, in part for some of the reasons others mentioned (if at some point she goes into a retirement home and needs to use her assets to pay for care).Are you able to pay for her home for 10-20 years? 

And that's one reason why I hate California and am leaving.

I personally do recommend Columbus Ohio for many reasons.

This is the reason homes are so much cheaper than cost to build.

Stating that they are using the mortgage of the investment property as a reason because it would put me above their threshold.

Also, if you have a below market interest note, if you wanted to sell that note for any reason in the future for liquidity you would be affecting the value of that note negatively.