There are several issues here.
The first is that your qualifying relative can't earn more than $4200 in 2019. If she earns more, you can't claim her.
The second is that if you do claim her, you don't qualify for the Child Care Credit. The payments for care cannot be paid to your spouse, to the parent of your qualifying person, to someone you can claim as your dependent on your return, or to your child who will not be age 19 or older by the end of the year even if he or she is not your dependent. You must identify the care provider(s) on your tax return.
The third is yes, she must file a tax return and report this income. If you had compensation not reported on a W-2, you would report it on Schedule C Profit or Loss from Business. You are considered to be an Independent Contractor.
You could use the Deluxe Edition if you did not wish to claim expenses or The Self-Employed Edition to claim expenses.
