She breaks it

Carrying a secret around her neck has made Hermione fidgety and anxious to a new extreme. She can barely make it through a class without reflexively clasping a hand around the Time Turned to confirm that it’s still tucked away under her robes.

Hermione’s slender fingers pry and work away at the thin metal of the artifact around her neck over the course of her time at Hogwarts. Little does she realize that every twist and bend she puts the Turner through strains the metal a little closer to its breaking point. Eventually - as is inevitable - she grips the fragile amulet especially tightly, and with an involuntary jerking motion she pops the delicate device off of the chain around her soft neck. The ‘plink’ of thin metal snapping sends a jolt of terror through her, and she looks down in horror to see the valuable necklace in her palm, snapped in two.