A woman of German accent, her age is never revealed, but in Greg Rucka's novelization of "No Man's Land" storyline she is said to be 12 years younger than Gordon. Sarah's detective skills are shown during her attempts with Gordon to catch Batman, by guessing (correctly) that he is Bruce Wayne by virtue of his history and the money needed for Batman's arsenal.
A woman with a German accent remains ageless, but in Greg Rucka's novelization of "No Man's Land," she claims to be 12 years younger than Gordon. Sarah's investigative prowess is demonstrated as she works alongside Gordon to capture Batman, using her knowledge of his past and the financial resources needed for his equipment to deduce that he is actually Bruce Wayne.