I bet cost of postage back is far more than 2 quid.
Only possible to refund only purchase price IF she agrees to that little refund.
I would only try what Chinstrap suggests if buyer hasn't actually opened a case yet.
If she has opened a case then you've already got a black mark on your account. So in theory you could do what Chinstrap says since you've nothing to lose, but it probably means you being out of pocket as well as getting the black mark, what's the point?
If you insist that she send back, then you will be out of pocket 1 lot of postage, 1 lot of fees, 20 pence retained by Paypal, plus whatever Ebay charges for return postage (more than you paid, I promise). No way you're going to cover all that on resale if it only went for 2 quid first time, so I wouldn't ask her to send back.
To avoid actual neg. feedback and cut my losses, I would ask her to send pic of the offending hole, and then once I saw it, I would agree to refund her in full without having her send item back, and I would leave feedback along lines of "Sorry you were unhappy with the items" and put her on my blocked bidder list. cow