From Halopedia, the Halo wiki
Anna Gerov is a civilian daughter of UNSC Vice Admiral Gerov. Some kind of "incident" occurred between her and Lieutenant William Lovell, presumably a romantic affair. This incident was not detailed in Lovell's record, but it was significant enough to have him demoted in rank from Lieutenant to Ensign. Due to this incident, Lovell was stationed on the Archimedes, a remote scanning outpost in the Sigma Octanus system.