Continuity mistake: When being questioned, they put a picture on the table in front of Ziva. In this shot, she has her arms on the table, palm up. When the shot changes, her hands are now palm down. (00:21:20)
Continuity mistake: On the stakeout, Parsons asks McGee what the tracker on his phone does. When he does so, he takes a drink from his cup straw. When the shot changes, he is no longer having a drink. (00:08:40)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.