Reality Check
Keepin' it 100
Doubt their protection would just drop
As soon as a new President is sworn in, Secret Service would have no obligation to protect Trump's grown adult kids since they would no longer be related to the President. I think Barron Trump and Melania would still receive Secret Service protection; closest parallel would be JFK where Jackie Kennedy lost her protection when she remarried but JFK's kids still had protection until they turned 16.