If she worked and earned this money, it is considered to be her business by the IRS. She needs to enter Box 7 income on Schedule C.
Box
7. Shows nonemployee compensation. If you are in the trade or business of
catching fish, box 7 may show cash you received for the sale of fish. If the
amount in this box is SE income, report it on Schedule C or F (Form 1040), and
complete Schedule SE (Form 1040). You received this form instead of Form W-2
because the payer did not consider you an employee and did not withhold income
tax or social security and Medicare tax. I