A lot of people think they're going to love it here until they get here and realize visiting a resort (with 24/7 A/C and weekly pesticide spraying) isn't quite the same as really living here. 

I do have a different take on the idea that Adverse Possession should be considered only a tool of last resort.  

Resort /vacation type properties also have a huge beta, meaning they go way up when things are good, or way down when they're not.

Fighting with a tenant is always a last resort IMO...but that does happen.

So, getting him to voluntarily sign a mutual lease termination letter that you all three sign, would be best.Eviction would be a last resort, because she'd have to be named on it, and any eviction action that gets filed, would put her name on an eviction report database, and that would be awful for any future renting for her.If he won't sign with her still living there, the only other thing I can think of is to have her move out and break the lease. 

This is a last resort option but an option nonetheless.During the advertising process we decided to let the market set the price being we were over on the rehab we didn't want to leave any money on the table.  

I have had no problem renting out the unit out by myself via Craigslist and Zillow in the past, but have even resorted to hire a real estate agent.

These are resort locations, as I'm sure you are aware.

But, this is a last resort, because you won't have as much security deposit to use once she moves out.

I pay $1400 a year in taxes, $1250 a year in resort dues, and have it financed on a HELOC at about 2% interest only  (I currently owe about $125k).