Visible crew/equipment: When Gibbs and Ziva are in the "safehouse" Ziva set up for Ari, a crew member and his boom microphone are seen on the left of the screen, right before Gibbs climbs the ladder to remove the hidden camera spying on them. (00:30:10)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.