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

Long term rental numbers are hard to get cash flow with added in reserves for maintenance, cap ex, and vacancy.

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?

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.

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. 

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.

This included modernizing the kitchen with high-end appliances, upgrading bathrooms with spa-like features, and adding hardwood floors for a luxury feel Lessons learned?

If we can't find a solution, I think she will be OK with me adding her property under my own account, and then me paying her out monthly.