You do not enter a dependent child's earned income from wages reported on a W-2 or their income from self-employment on your tax return.
If the dependent child has income from wages on a W-2 they do not have to file a tax return if the income is $6,350 or less. However, if taxes were withheld they should file a tax return to get a refund of the taxes withheld. If they do file a tax return then make sure that they indicate on their tax return that they can be claimed as a dependent on someone else's return.
