Is she spayed?
Ours started carpet-eating with a vengeance when they hit their 'teenage' years and nothing we could do would stop them.
Once they were spayed, we managed to get them to stop (mostly). We used a combination of a chew-stop spray, and clapping/distraction every time they started, but it took several weeks.
Five years on and they still have the odd nibble, but they're not persistent and can be stopped easily.