My question is ... if it should show up, and she closes the case, will the defect remain?

Good question. Was your item sent with tracking? I presume if it was, would be much easier to prove when it was sent and delivered and easier make a case to have defect removed. Also taking into account the long weekend.

My item not as received was for a UK buyer, I refunded them straight away as it was sent as large letter, no tracking. I still think it may turn up though, as  it was posted late December.