Usually you arrange that with a neighbor.

I do not want to kick her to the street (she says they have no money left to make new arrangements). 

Or if you hire a contractor, and there is a younger guy in the crew that probably lives with their parents, much easier to arrange. 

So, in a nutshell, your arrangement with your relative and how the profits are split when properties are sold depends on the terms you agreed upon when setting up the partnership.

You need a PPM and a TIC arrangement for holding title to the property.

You are paying for your son's living arrangement by giving him $200,000 and she is getting her rent paid for by some other guy.

I currently own a 9 unit multi-family and a mixed use fourplex both of which has commercial financing, so I'm familiar with the typical financing arrangements and valuation. 

I think that's enough to arrange a meetup and network. 

Yes, this is an unfortunate situation however the tenant knew this was coming and failed to make other arrangements. 

As a quick addendum, the last time I was in small claims court trying to recover several thousand dollars from some tenants, I brought with me several pounds of documents sorted out within about a dozen folders.After the Magistrate asked me to state my case, I spent at least 30 seconds arranging the neatly-labeled folders out upon the Plaintiff's desk before I said a word.