Twila Nova is the Federation's 5th Vice Admiral, who is highly skilled in battle and strategic. At the end of the Federation's eternal Multiverse War against the Rebellion, her purpose of commanding a fleet was nearing its end, but it doesn't seem like either her or the Admiral are keen on stepping down yet.
When not commanding the Federation, she is often with her sister, Crystal.
Ironically, despite her high rank, she wasn't too fond of Admiral Tully, but she tolerated him enough in wartime.