Mother Rell held the distinction of being the most senior member of the Singing Mountain Clan, part of the Witches of Dathomir, with her age nearing 300 local years, which translates to approximately 400 standard years. Her great age caused her abilities to perceive the past and predict the future to sometimes result in disorientation.
Rell engaged in negotiations with Yoda concerning the wreckage of the Chu'unthor after he rescued her. Yoda entrusted the records to Rell, informing her that a Jedi Knight and their apprentice would eventually seek the records within the ship. Her role was to provide these records to the Jedi after they liberated her planet from the Nightsisters.
Upon the arrival of Luke Skywalker and Isolder on Dathomir in 8 ABY, Rell identified them as the individuals Yoda had foretold. She then made a prediction about Luke's future marriage, the birth of his children, the establishment of the Jedi Praxeum, and the eventual demise of Isolder.
Following the Nightsisters' downfall, Rell gave Luke the items that Yoda had left in her care and died peacefully not long after.