If they have no other properties then its a definite no go as they have zero skin in the game and zero incentive if it goes bad. 

This ensures they have skin in the game and will (probably/hopefully pass).

This is my passion and I have to admit it gets under my skin when people waste other's time or approach this like a joke.  

In my experience, there's a very good chance that the Tenants were problematic over the years, the PM hasn't inspected in a long time (if at all), and there's damages beyond ordinary wear-and-tear to deal with.There are many ways to skin a cat, but I'm sharing my experience on what the best option is.

Private lenders would allow you to do this but not traditional banks as they want you to have skin in the game with your equity down payment.

This indicates they have enough skin in the game to motivate them to offer fair terms.With 20-30% equity, the seller can likely offer favorable terms.Conversely, a deal with a seller who has less than 20% equity remaining would be riskier for the buyer.

It kind of sounds like you're a little thin skinned and allowed their whining and unkind words to get to you.

It's like step 5/50 because you're already a home owner and been through the closing process.It's on you to decide how much you want leverage, how much skin you have in the properties (probably a minimum 20%), and what level of PM you can or want to handle. 

Your daughter may contribute her savings, and share ownership so she has skin in the game. 

As to the emotions, grow thicker skin!