As Rick says, a child that is EMPLOYED (employee) by a parent is not subject to Social Security and Medicare.

If the child is an Independent Contractor (which seems extremely unlikely) the child IS subject to SE tax.

CHILD WAS 1099 OTHER INCOME , SO HAS TO BE WAGES OR WILL BE NOT AFFECTED BY STD DEDUCTION

They should NOT have been issued a 1099MISC as other income if they are working for their parents.

Thanks, will inform client..