Oops. To clarify, I don't yet know how much she's selling it for.The ticket cost £47 from the ticket office, so if you're not a concession then you'll need to pay the difference to make it up (IIRC a full-price ticket is £62, so that's an extra £15).
I guess if there's only one person interested, it'll go cheap; if she gets trampled in the rush then she may hold out for making a small profit on it. :-) Or she may just ditch it for the list price on a first-come first-served basis. Post here anyway if you're interested.
Graham.