One program we've actually used for clients is a bit odd and it is somewhat expensive, but it does work.

If you open up the schedule and another guest books, then I agree with @Chris Seveney that a credit (assuming the new booking is at a discounted nightly rate) would be more than generous and also lets her know that you are a reasonable host if she does decide to book again in the future.It just feels odd that she would be contacting you the day of check-in to cancel due to the weather, when she could have communicated this days ago.

I'd encourage you to talk to a CPA before choosing a path.Since you are already an agent, the odds are good you could qualify as a real estate professional status (REPS) for tax purposes. 

How comfortable are you with that risk and are the odds in your favor or against you. 

This happens every day, there's lots of marketing activity to say no to revenue, and oddly prior to anyone bringing it up you're screaming from the hilltops that Spark doesn't accept this money - well time will tell.

but i've always thought, that's like saying you can play basketball in the NBA because LeBron does.  

If often more that they are abandanoning the property to the government because there is some type of constraint, i.e. there is a street light oddly placed in the middle front part of the parcel, there is a creek or wash (which means environmental permits would be needed), there is lack of true legal access, zoning problems, etc. 

Frankly - this space has become extremely saturated over the last 10 years - so the odds that you find this one "diamond in the rough" deal is relatively low all things considered. 

I could totally see if this was for a new acquisition but for a cash out where I have 100% equity right now this feels odd. 

Rotunda is also really close to the water where the last hurricane hit, so the market there in general might be a bit odd right now coming into another hurricane season.