You can use it on your next ticket or maybe buy some miles. You don't have to use the whole amount of the ticket. Just buy something now and get the voucher mailed in and she'll get a new voucher good for 360 days less whatever you bought with it. Buy a fully refundable ticket and use the voucher to pay for part of it; the new voucher will be good for 360 days and then you can continue to recycle it through all of your trips.