I'm thinking since she's read SFL, she's already sold on taking control of her finances, and maybe Brandon's book is next?  

@Raymond SantosNumbers seem a bit too conservativeI don't know the conditions of the property, but if I was running the numbers, I would use the following:Monthly:Revenue = $2,550Expenses:Mortgage: $1,347 (300k at 3.5%)Insurance: 150 (1,800 a year)Maintenance: 200 (should cover lawnmowing, pest control, hvac, and a few other things)CapEx: 200 (this one is a wildcard, but 200 is very conservative from my experience)PM: 250Vacancy: 107 (half a month a year)Total Expenses: $2,254You net $250 a month.

Control those assets or someone else will. 

I just want to be free from this high mortgage payment of $2300 + maintenance & repairs and debt that has controlled us.

And, intent matters, but, by itself, is not controlling. 

My state has no rent control law. 

Zoning approval, neighborhood pushback, utility approvals, flood control, offsite street improvements may be required, engineering, etc. 

There is always the chance that they start to gain more control over your property than you have, but that's besides the point.We are still in a very strong seller's market right now, or demand is far exceeding supply.

A friend of mine had an idea to buy "smaller cell sites" since the larger towers seem to be out of our price range as well as dominated by larger players.

Maybe it will, but I don't have direct control because it is being put on the seller.