Star Trek: The Lionhearted Wiki

Mary DeSoto was a Human serving in Starfleet during the 24th century.

Many of her family served in Starfleet, including her great uncle, Robert DeSoto.

By 2373 she was serving as part of the USS Brazen's medical staff when Gedna Tachion assumed command.

She was one of nine survivors after the ship was destroyed during the Battle of Tyra, and was incarcerated at the  Hekiss Prisoner of War Camp for several months.  She was the senior Starfleet medical officer there.  She received a commendation for her work at the POW Camp.  ("Familiar Faces")

After being rescued and declared fit for duty, she was promoted to Lieutenant and Chief Medical Officer of the USS Camelot.

On stardate 51905.4 she was part of an away team to the moon of Perdition to rescue stranded crew members of the USS Potemkin and IKS Krohtal.  ("Perdition's Flames")