Lela Dax was a member of the Trill ruling council, only the fourth woman ever to be part of that governmental body. She campaigned for her position pledging to be an advocate for "the disenfranchised unjoined," which earned her the disdain of some older, more conservative councilors, such as Darzen Odan.
Lela Dax was the first councilor made aware of the arrival of a L'Dira vessel in Trill orbit, which refused to honor Trill's wishes to avoid outside contact. Dax, disregarding the council's resolutions on how to deal with the aliens, attempted to communicate with the L'Dira. For this, she was charged with treason, but acquitted by the council as they realized hers was the correct course of action. (DS9 short story: "First Steps")
Lela once spent a year teaching on Andevian II. During her time there, a virus struck the planet which infected hundreds of thousands, including her daughter Milayn who died from the illness. A new regime took over the planet and blamed her for the outbreak. They ordered Lela to leave the planet and she and her family returned to Trill with her daughter's family. (DS9 novel: Wrath of the Prophets)
Lela's consciousness was embodied by Kira Nerys during Jadzia's zhian'tara. Lela had a habit of walking with her hands clasped behind her back, a habit which Jadzia later inherited. (DS9 episode: "Facets")