Unfortunately, she doesn't have a choice. IRS Pub 501 says that you must file if you have net self-employment income of more than $400. You must file and pay self-employment tax even if no ordinary income tax is owed. See Table 3, page 5, IRS Pub 501 at this link:
You can find IRS Pub 501 at this link:
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/pub/irs-pdf/p501.pdf">https://www.irs.gov/pub/irs-pdf/p501.pdf</a>
When you claim the credit for it, you must list her SSN and the IRS will check to see that she files and reports the income.
