Chinchilla won't eat pellets?

Hello, a friend gave me her chinchilla over a week ago. I've been trying not to worry, but she hasn't touched her pellets, and is only eating hay. She has been on the same pellets for the 2 years my friend had her with no problems.



Should I give her more time before I completely freak out, or has it been too long already?



What can I do to encourage her to eat?