If Baron stays in HS in Florida (unless, he graduates soon and I have no idea when that happens,) Melania will stay in Florida
He graduates this year and he WILL be able to vote for his father, in November.
Barron's birthday is March 20 when he turns 18. He should graduate HS at the end of this school term. Presumably he will then go on to college where he will almost certainly want to start living his own life. Hopefully his mom will not follow the young man to wherever he decides to go after HS.