Ensign Brackett was an operations division officer assigned to the USS Enterprise in 2258 of an alternate reality.
In 2259, Brackett was present during incident with "John Harrison" and the USS Vengeance. She reported to acting captain Hikaru Sulu that the signal of the K'normian trading ship with Kirk, Spock, and Uhura aboard had cut out and she was unsure what happened. (Star Trek Into Darkness)
Brackett was played by Amanda Foreman, who previously played Hannity.
This character was only named in the source's end credits.
The Star Trek Encyclopedia had entries for both "Ensign Brackett" (4th ed., vol. 1, p. 100) and "Hannity" (4th ed., vol. 1, p. 325). It is clear in the entries and the notes accompanying the entries that the authors of this reference work believed the actress was playing two characters, not one.