OP, that will happen so many times!

After few years you get used to it - just look at as you had a real store, customers come in, waste your time, try just about everything on - and leave without buying anything.

Your buyer is actually a bit rare - to offer to pay your costs - hardly anyone does. They just shut up about it, don't pay, you can't really force them to and why would you want to? Just another headache - you need that like a hole in the head.

In this case I wouldn't let her pay any fees, you'll get them all back from Ebay - just an offer from her was nice enough.

In any case, you'll need to relist the boots, wouldn't you do it sooner rather than after 8 days?

Send her a cancellation and be done with it.

Best of luck with it.

Cheers.