Even better, the tenants are mother/son relation (sarcastic lol).

Does not hurt your mothers tax side and you benefit from not having to have cash for DP or closing costs!

Your situation isn't troubling at all to me with a mother and her one kid in a 1 br.

I think it was because they moved a single mother in a house with no furnace during winter.

I previously had a property manager that put in a retired grandmother, mother, and working age daughter.

My mother-in-law will be starting a new job next after an almost 2 year long stint back working under the table, but her own physical ailments are becoming worse.Their combined income is only $21/hr.They owe $70K on a home worth ~$170K that was free and clear, but stupidly signed onto one of their parent's cash-out refis before death.There are additional credit card debts that are nearly paid off (around $5K I believe).With abysmal credit, selling the home and renting would likely be a wash, if not a worse situation.I would like to see them grow a saving account of some type.

However, I went that route once, and my furniture and 73 yr old maple hardwood floors were destroyed by a puppy they sneaked in that turned into a Great Pyrenees, a third unapproved roommate with drugs, and an entitled kid whose mother thought he could do no wrong. 

'private money' on it's face is private. i'd loan money to a trusted friend or colleague today at 5% if it made sense and the risk was low, and i certainly would not charge my mother any interest at all :) what typically happens with these offers is that the verbiage is intentionally misleading. 100% financing would make one think they do not have to bring any of their own money, which is not always the case.

When I was considering one purchase which was a mother/daughter style I was cautioned that the spare unit could not be rented legally except to a family member.

I had watched my mother-in-law buy a bunch of rentals, and I thought 'I really want to do that!'.