If you take it from the lender you owe it back to them.

As I mentioned in an earlier reply, if the tenant owes money for damages or rent, they are liable.  

You should make sure that the rental revenue meets all of your costs, including the mortgage payment, property taxes, insurance, maintenance, and vacancy allowance, since monthly rental prices might range from $1,000 to $1,600.Property Appreciation: Take into account the market's expected and past rates of property appreciation.

Since Florida has no income taxes...

For more precise estimates of rental revenue, think about speaking with nearby property managers or real estate brokers that focus on rental properties.Closing costs: Compute the closing expenses for the duplex purchase, taking into account attorney fees, title insurance, property taxes, appraisal fees, and loan origination fees.

I thought maybe she’d like the increased income and reduced liability as she approaches 90 years old but I see the tax issues might be too big an obstacle as she does seem pretty well off. 

I am wondering what are the tax implications for this individuals (most of them are from Spain). 

is it illegal to sell my Tax Deed by quit quitclaim Deed?

@John Davis - his niche is tax liens, and I'm sure he knows a ton about tax deeds as well . 

So far, when I look at a property I tend to look at: what did other properties in the area sell for, how are the schools (I.e if I want to attract families), how much does rent typically go for in that area, how much is property taxes in that area,etc.