WARNING: The following contains spoilers for Zack Snyder's Justice League, now streaming on HBO Max.
Cyborg is easily the hero with the most additional development in Zack Snyder's Justice League. That includes a flashback to his origin story, which focuses on his experience as a star athlete and his relationship with his mother. A part of the flashback mentions that Victor Stone hacked into his school's grading system to improve a friend's grades. The name of that friend is Sarah, which instantly recalls two of Cyborg's love interests from the comics. Here's a look at the history of both Sarahs, which one the film is likely referencing and how this may have factored into a potential Cyborg movie.
Sarah Simms
Sarah Simms debuted in The New Teen Titans #8 and, like Cyborg himself, was created by George Perez and Marv Wolfman. She looked after children with physical disabilities, and met Cyborg when a child's wayward ball hit him in the head. Cyborg was initially worried the kid would be afraid of his mechanical body, but instead he was jealous because his prosthetics were primitive in comparison to Cyborg's. The superhero continued to hang out with Sarah and the kids, and she became a recurring part of the Teen Titans' lives.
She was teased as a love interest for Cyborg, but Wolfman and Perez decided against going in this direction as they felt interracial pairings had become too much of a trope at the time. Sarah has yet to be a major part of any of the Teen Titans adaptations, though in an episode of the cartoon series, Cyborg traveled back in time and fell in love with a barbarian woman named Sarasim who was meant as an homage to Sarah Simms. Likewise, the Teen Titans Go comic book that supplemented the show's continuity introduced its own version of Sarah who counseled children with disabilities like in the original comics. This version of the character eventually had a romance with Cyborg.
Sarah Charles
Sarah Charles, who debuted in the sixth issue of the second volume of The New Teen Titans, was also created by Wolfman and Perez. She was introduced when Cyborg briefly had his mechanical limbs replaced with more human looking prosthetics and she helped him rehabilitate. From then on, she became one of his closest confidants and, eventually, his love interest. The relationship became more long distance, however, and seemed to end once Cyborg became Cyberion.
The New 52 rebooted her to be a prominent part of Victor's life earlier on. There, she was an intern at S.T.A.R. Labs who assisted Victor's father Silas in converting him into Cyborg. This incarnation of the character appeared in recent animated DC movies, as well as the third season of Young Justice.
DCEU Sarah
The Snyder Cut's use of the name Sarah in reference to Cyborg's friend is ambiguous. However, the backstories of the two Sarahs in the comics provide evidence for this being Sarah Charles. Sarah Simms' two main variations only met Cyborg after he became a superhero, and she also hasn't been seen since the New 52 began. The New 52 version of Sarah Charles, on the other hand, knew Victor before he became Cyborg, which matches the situation in the film.
The New 52 incarnation of Cyborg is also the one that most informed his DCEU depiction, namely in terms of his being powered by a Mother Box. As a result, it would make sense to subtly introduce one of Cyborg's New 52 supporting cast members. It's likely Sarah Charles would have been formally introduced in the solo Cyborg movie Snyder had planned, replacing the character's father as the person most knowledgeable about his mechanical components and developing a romantic relationship with him. Sadly, it's unclear if we'll ever see that film or either Sarah in the DCEU, leaving them, much like Ryan Choi, as elements Snyder established that never fulfill their promise.
Zack Snyder's Justice League stars Ben Affleck as Batman, Gal Gadot as Wonder Woman, Henry Cavill as Superman, Amy Adams as Lois Lane, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, Jeremy Irons as Alfred Pennyworth, Diane Lane as Martha Kent, Ray Porter as Darkseid, Ciarán Hinds as Steppenwolf, Jesse Eisenberg as Lex Luthor and J.K. Simmons as Commissioner Gordon. The film is currently available on HBO Max.