Commander Sheldon followed Captain, then Admiral, Stephen Fairchilde from Starfleet when the DFA was formed.  She began as an ensign in both Starfleet and the DFA and has continued to advance through the ranks, ever remaining loyal the the captain she followed from the beginning.   The DFA Cromwell-B was her first command level position.

 

Following the death of Admiral Fairchilde after the Nal'G attack on Babylon Commander Sheldon retired from the DFA.  She was reinstated by Admiral Tirapau, and after a year long staff position as fleet recovery director (Following the devastation of the DFA fleet from the Nal'G Planet attack), was advanced to Fleet commander, directed to control fleet actions and coordinate Fleet level mission.  Youngest and lowest ranking "big five" members.

 

Quote:  "Give me results, not excuses."