New Story Idea!

Plot:

The main character is a girl who works as an internship for the FBI and her first mission is to protect the family, without them knowing. She had to get close enough to at least one of them so she can be on the inside.

Q:
Should I use OCs or make the family the Jonas Brothers? I have had this idea in my head for awhile and I really want to incoroprate it somehow to make a story,. I posted a poll on Quizilla a few weeks ago, but I only got 6 responsed and its a tie. I need a tie-breaker! Please comment at the bottom to help me out :D thanks!