We'll need more information to help you. What is her set-up like? Temperatures, humidity, etc. What do normally feed her and how often? How long have you had her? Is she maybe about to shed? (reptiles about to shed sometimes won't eat)
You need to go to the pet store and ask them what is the right thing to do: best of luck
Do not trust what the pet store tells you. They are hired to make money for the company.