Putting in a ramp, adding grab bars in bathroom, raising the sink height, etc.  

Do you understand the added complexity, work involved, and costs? 

If you remodeled, added a room, replaced a roof, painted, boosted the curb appeal, etc. that's a different story.

So she took that extra space, added a wall and a hidden door and poof!

But I will be honest, the rentals I have been added the last 2 years here in DFW have negative cashflowed.

It all started with removing some interior walls and changing the floor plan, removing a chimney, adding a bedroom and bathroom, installing patio door to the backyard, and completely renovating every other interior element What was the outcome?

Adding a 1/2 bath, new roof, central air or other typical improvements will increase the value of the property. 

I'm in the Tampa Bay area and I will put an ad on Craigslist, Indeed or post in a group on Facebook for AirBNB/STRs. 

Which makes my answer, as opposed to yours, applicable.Especially since I qualified mine by adding "...unless she adds more real estate work"Your argument reminds my of an old joke:- Doctor, will I be able to play violin after this surgery?

Seems like the best way to avoid added fees, points and middle men though.