13-01-2018 3:54 PM
It's not up to a successful buyer to tell you what to do [whether or not bidding for a friend]! She is responsible to go through with the purchase.
You have incurred eBay's fees and the only way is to open a non-payer case and close after 4 days. Only then can you offer to the underbidder [who is not obliged to accept] or to relist.
The original "buyer" will get a defect and you will get a fee credit. If you sell to the underbidder then you will be charged again [presumably at the lower bid]