I haven't got anyone locked on my account so can't easily show a screenshot, but she needs to look for an ice cube image at the left of your lock on her side if she's the keyholder. If she's found out how to add time or cards, and do other updates then that's the area of the app where she'd find the ice cube.
If she's not the keyholder and you're running a solo lock or have a bot for a keyholder then neither of you can unfreeze it. You have to wait for the freeze to end.