As the long-time leader and host of uber-exclusive Bottomfeeders conference held semi annually in Santa Barbara for well over a decade, I think I'm qualified to weigh in. 

Many agents try to get their clients under an exclusive working contract.

@Will Rodgers We used to use unlicensed contractors almost exclusively since they were cheap compared to general handymen but after being in the business for a while we found that there were pleny of insured, legitimate handyman that worked for the same rate. 

For example, you can have a business card with your name, and a tagline underneath it, "I work exclusively with investors!"

I was also a year within being a millionaire, and remarking to family and friends that I just joined this exclusive coaching program.

Look for the signs: unmowed lawns, boarded up windows, newspapers piling up from vacancy, etc etc.

@Brandon Turner I definitely ran numbers (and do often) through you wonderful calculators, found exclusively at BiggerPockets.com.  

I like being exclusive. 

Protect yourself through her will and maybe a proper exclusive option to purchase that renews or something.  

Only way I'd put down most of the money is if it was such an awesome deal making so much $$$ and the JV had exclusive rights to it.