Thank you for your help. That seems to have worked in getting the money back to her. I still can't find any record of it in the normal interface, but it's also still in Pending status, so I'm guessing that's why. I'm not entirely clear in how to link it with the original payment, but since it's a reversal, I'm hoping that happens automatically (creating a Refund Receipt didn't work, because it wanted payment details).

I also noticed in the first link you sent, in the "Refund a credit card payment for a sales receipt..." link apparently an option should appear to edit the refund amount, instead of refunding the entire payment. If that's correct, would that be a more streamlined approach or would it then ask for the credit card information?