This page contains information regarding Star Trek: Picard, and thus may contain spoilers.
Agnes Jurati speculated that her sister was created via fractal neuronic cloning, a radical idea proposed by 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")