Second Lieutenant Maria Ross is put in charge of taking care of the Elric brothers during their stay in Central. She and her partner Brosh were assigned the task of guarding the Elrics due to Scar's return in Central and his previous attempt on Ed and Al's lives. Almost immediately, she takes on the role of a parental figure. She tries to give guidance to the brothers whenever she can. She took a liking to Ed and Al, and risked her life to calm Ed down when he was absorbing the red stone material inside laboratory 5. Both she and her partner Denny Brosh work under Major Alex Louis Armstrong.
Source: Wikipedia