The kids do have Secret Service protection, but physical harm is not the Trump kids' biggest threat...they are in jeopardy of facing long prison terms for financial crimes...this is in addition to Jared and Jr. having criminal exposure for that Trump Tower meeting with the Russians...
Jared and Jr most likely regret the day, a few years ago before daddy started his presidential campaign, they publicly revealed that the source of the financial support for the Trump enterprises is Russian banks...
The long-time accountant/CFO for the Trump family, co-executive of the Trump Trust that covers the Trump Organization and Trump Foundation, has been interrogated by the SDNY and NYAG and granted immunity...a bad turn of events for the execs above him...
Trump's kids, Eric and Don Jr, are heavily involved as co-executives with that CFO of the Trust, in the day-to-day management of those Trump business enterprises, both of which are under criminal investigation... the Trump Foundation has been under civil litigation for months...