where do I put in self employment income?

That should be on Schedule C.   You either need to change her income or expenses to change the Net Profit or Loss.

How to enter income from Self Employment
https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/26653

Where to enter business expenses
https://ttlc.intuit.com/community/entering-importing/help/where-do-i-enter-my-self-employment-business-expenses-like-home-office-vehicle-mileage-and-supplies/01/27109

Her net income comes from her gross income minus her expenses.  In order to change the net income you will need to update her gross income and expenses in the business income and expense section.  To get there select the following:

1. Federal
2. Income and Expenses
3. Show More next to Self-Employment
4. Start next to Self-Employment