This page contains information regarding Star Trek: Picard, and thus may contain spoilers.
Dr. Agnes Jurati speculated that her sister was created via fractal neuronic cloning, a radical idea proposed by Dr. Bruce Maddox that suggested a positronic brain could be created entirely from a single positronic neuron, in this case, from the late Lieutenant Commander Data. Fractal neuronic cloning produced twins, and Soji possessed a necklace identical to one owned by Dahj which contained the interlocking circles symbol for this cybernetic technique, which she recounted as having been given to her by her father. (PIC: "Remembrance")
While working there, she met Narek, and quickly entered into an intimate relationship with him, unaware that he was part of a clandestine operation to obtain information on the whereabouts of biological androids such as Soji and her twin. (PIC: "Remembrance", "Maps and Legends")
The spatial trajector transported her and Picard to Nepenthe, where she was greeted by Deanna Troi, Will Riker, and their daughter Kestra Troi-Riker. There, she got to know the family, fully realizing that she was an android when Kestra asked her if she really was one. When she went to lunch, she tilted her head, leading to Riker to realize she is the daughter of Data. Later, she leaves with Picard onto the La Sirena. (PIC: "Nepenthe")
After the trip through the Borg tunnel, the La Sirena crashed on the surface of the planet Coppelius. She went to the wrecked Borg cube that was on the surface as well. Afterwards, she traveled to Coppelius Station where she met other androids and her father who created her. When Picard told everyone there would be a ship available to send them away to safety, she sided with the androids so that their conviction in hope is not in doubt. (PIC: "Et in Arcadia Ego, Part 1")
She commenced construction of the beacon meant to signal the synthetic lifeforms in another dimension. While constructing the beacon, Soji was momentarily distracted by Narek, who had returned and caught an energy weapon designed to destroy it, through it away. She later was convinced by Picard to stand down from its construction and willingly destroyed it.