First of all above anything I am a Patriot. I whistle while I work, because whistling is my work. world's greatest whistler. Want Freedom
Maybe she was arrested, but they're letting her work for the president for the movie for an extra wam wam or zoom zoom. So the Marshals are just up her ass all night and day to make sure she doesn't screw up.
The entire capital is surrounded like a military compound atm. I wouldnt go so far to say shes "arrested". Its just interesting. But I will say that its very odd and out of place...
In a game of chess you make moves that are not logical to your opponent. So they feel like everything is fine and protected... Why not assign the group of people to "protect" her just to end up arresting.. IDK just a theory.