Maria Ross

Second Lieutenant Maria Ross (マリア・ロス, Maria Rosu) is an Amestrian soldier stationed in Central City under the command of Major Alex Louis Armstrong. Described as honest, decent and caring by her superior officer, 2nd Lt. Ross is an exemplary soldier capable of balancing her dutiful professionalism with her personable human side.
Ross first appears when she and her partner, Sergeant Denny Brosh, are assigned to escort and guard Edward and Alphonse Elric in place of Major Armstrong after the three alchemists arrive in Central. Ross and Brosh, just as many others, initially mistake Al for the famous "Fullmetal Alchemist" and find themselves confused as to the brothers' idiosyncrasies, but come to an understanding with them relatively soon. When the Elrics head toward their initial goal of the National Central Library's First Branch, Lt. Ross is given the unhappy task of informing them that the building and all the precious research materials inside had been destroyed the day before their arrival in a fire whose origin appears to have been arson.
Lt. Ross and her partner continue to guard the young alchemists as they find other means of acquiring and deciphering the information they seek, and are further shocked by the Elrics' casual rapport with such high-ranking officers as Lt. Colonel Maes Hughes as well as the exorbitant amounts of money they are able to throw around as part of their yearly government research grant. But the real shock comes when Ross and Brosh learn from the horrified Elrics that their code-breaking is complete and that the fruit of their labors has revealed that the Philosopher's Stone is made up of live human beings.