If she wants to work, let her work. She may thrive or she may hate it and try again when she's older. I wouldnt do anything to discourage a kid developing a work ethic though. Good on her! It will teach her responsibility.

It will also be a good opportunity to teach her some financial skills, like saving. I'd say she can work if she agrees to put 10% of her net income into an untouchable, high interest, online account that only you know the password to.