@Angela Simon, If it wasn't your son there is a small chance that your accountant would let you purchase the 50% of the property you don't own. 

The property is worth exactly what it is with zero STR rental income.

Because the property tax as a non-owner occupied property is about 3-4 times the amount of a owner occupied property.  

The first thing here would be the regulations and laws governing acquiring properties, managing properties and selling properties.

Define your minimum cash-flow to hold this property. 

Its much harder to turn a property around in 6 months expecting to have 100% of your money returned back to you - but if you focus on the right property focusing on highest and best use with an ADU add (like mentioned), in-fill/lot split, or other rehabs - then hopefully a semi-decent property like that will perform like a champ in a few years. 

@Ngozi IwunzeOne way to avoid capital gains is to turn the flip into a rental after the rehab and then do a 1031 exchange into a more expensive property. 

Does Obie insure property in the name of an LLC?

Roofstock, the property owner or the property buyer?  

The property or properties will be in Florida and/or Alabama.