Any unearned income, not just investment income, is subject to kiddie tax.   The kiddie tax is on the kids return, with the 8615, you dont put the kids unemployment on the parents return.

Going to be a lot of teenagers that need to pay the piper this year.   They received lots of money they wouldnt normally have received and way more than they could have ever earned working in that period of time, so Im sure they can afford the taxes.