Dr. Ana Stelline is a character first introduced in Blade Runner 2049.
Following an investigation conducted by LAPD Officer K, it is discovered that a child was born from a Nexus replicant model in the year 2021. As the events of Blade Runner 2049 unfold, Officer K discovers that memory designer Dr. Ana Stelline is, in fact, the first replicant-born child he was tasked with terminating by Joshi, who fears that its existence could lead to a bloody war between the human race and Nexus replicants on Earth.
Rachel's capabilty to breed was, in Niander Wallace's words, "Tyrell's last trick", as the science and technicalities behind this achievment in replicant design and development have escaped Wallace despite his best efforts.
Stelline is a subcontractor under the Wallace Corporation headed by Niander Wallace, working as a memory designer at an "upgrade center" named "Stelline Laboratories".
Dr. Stelline is reunited with her father, Rick Deckard, following Officer K's daring rescue of him from the hands of the Wallace Corporation.