Ensign Kristin is a young Enterprise-D officer treated by Beverly Crusher for a holodeck diving injury at the start of Conundrum, shortly before the whole crew lose their memories.
Kristin appears in the fifth-season episode Conundrum. In the opening minutes she is in sickbay, having hurt herself attempting a dive from the Cliffs of Heaven in a holodeck programme, and Dr. Crusher gently suggests she try a less punishing pastime.
Moments later an alien vessel scans the ship and every person aboard forgets who they are. Kristin, like the doctor treating her, is left with her skills intact but no idea of her name or position, and is among the confused patients and staff in sickbay as the crew try to work out their roles.
She is a small human touch in an episode about identity, one ordinary crew member caught in the Satarrans' scheme to use the Enterprise against the Lysians.