Minuet "Min" Riker was the wife of William T. Riker, mother of Jean-Luc Riker and ship's counselor of the USS Enterprise-D in a holographic simulation of the future created in 2367 by the alien Barash. In this simulation she had died in a shuttle accident in 2381.
Min Riker's existence made Will Riker realize that Barash's first simulation set on a future Enterprise-D was unreal; Barash had examined Riker's memories and determined Minuet to be a real woman from his past. Min was, in fact, created from Will Riker's memory of Minuet, a holographic fantasy woman designed for him by the Bynars in 2364. (TNG: "Future Imperfect", "11001001")