Click through the screens under the "Child's Income (Under Age 24)" section (Personal income > less common income > Child's income) until you get to a page that says "Other Earned Income" with text that says "The total for (name) for all earned income from wages, business income, and farming, is $XXX. Enter any other earned income that was not included in this amount." In that box, I entered the income from schedule k-1 self-employment earnings that I had already entered elsewhere in the software. You would enter any EARNED income in this box not already accounted for in the $XXXX number the software displays on this screen, despite entering the earned income elsewhere on the return.
