For an IRA contribution. If you only have self-employment income you can only contribute up to your net profit reduced by the deduction allowed for one-half of your self-employment taxes. See IRS publication 590 http://www.irs.gov/pub/irs-pdf/p590a.pdf
So check 1040 Schedule 1 line 15. You have to deduct that amount from your Schedule C Net Profit. That will give you the allowed contribution for self employment & 1099NEC income.
And by the way, she's doesn't have a choice. She has to file her own return got self employment income. Even if she doesn't owe regular income tax on it she owes self employment tax on a Net Profit of $400 or more.
Be sure on the dependent return you check the box that says you can be claimed on someone else’s return.
