First, make sure you/she is logged into the iTunes Store using the account ID and password that was set up, or used, when the card was redeemed. If you are, try logging out of the account and back in.
If you're sure you are viewing the correct account and logging out and back in doesn't help, go to the Purchase History and review her purchases to make sure that she should indeed have a $25 balance left. iTunes doesn't always refresh the balance it shows, so it's possible she spent the money and it just wasn't being reflected in the display. This display error can usually be corrected by logging out of the iTunes Store and then back in.
If you confirm that she should have additional balance but the iTunes Store isn't showing it correctly, send a message to the iTunes Store customer service department through the form at the bottom of
their Gift Card FAQ web page and explain the problem to them.
Good luck.
