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.

Maybe a manager would consider discounting to 8%.

The main difference is, as a wholesaler, you'll ONLY be able to work with folks selling their homes at a discount.

He is distressed and will sell at a discount in exchange for speed.

If you want to be that involved, go find one of those hungry discount managers desperate for the work.

Mine offers a discounted rate when I used them.

There are discount listing services.

And she’d get a discount as some of the sales money would come back to her. 

Most new investors lose money because they put too much into the rehab or they don't buy it at enough of a discount or they overestimate what they can sell it for.

It's widespread practice in the Real Estate Syndications industry to compensate bundlers by selling them their shares at a discount to par.