Admiral Raner was a 24th century Starfleet flag officer. She served as the Chief of Starfleet Security in 2370.
Raner was responsible for ordering Admiral Erik Pressman to recover the USS Pegasus and further experimentation on the prototype for a Federation phasing cloaking device, which had been lost in 2358. Due to the sensitive political nature of the experiment, she ordered Pressman to keep the effort a secret, and gave written orders to Commander William T. Riker to assist him without informing his captain, Jean-Luc Picard. (TNG: "The Pegasus")
This character was only mentioned in dialogue.
Depending on the circumstances or outcome of her involvement, she may or may not be the same female Chief of Starfleet Security who was later mentioned in Star Trek: Deep Space Nine and Star Trek: Voyager.