The original DL ticket, if unused should represent a credit available for 1 year. There will be a change fee to re-issue it for a future date, and it can only be used in her name, but the entire amount is not lost assuming she will need to fly somewhere in the next 12 months on DL.

Retain the original record locator and ticket number for future reference and call an agent to confirm the credit. A refund however, is not going to happen unless on a fully refundable $$$$$$$ ticket.