In the DC Comics, Mary Elizabeth "Bette" Kane is the original Bat-Girl and served as Batwoman's sidekick and Robin's counterpart. Growing up she would adopt the alias Flamebird (and later Hawkfire) in response to her counterpart's development as Nightwing. In the comics she is Kate Kane's younger cousin instead of her step-sister.
Production assistant Amanda Smith was paralyzed while working on the set. According to the woman's GoFundMe page, Smith was working on set when a bucket of a lift lowered onto her head, trapping her beneath it. She underwent significant spinal surgery and currently cannot feel anything below her waist. However, there is hope that she will regain sensations in her legs with the proper therapy. Smith is unable to work for the foreseeable future, and the money raised through the GoFundMe will help her get through this difficult time. The campaign had raised $34,380 out of a $50,000 goal.
Ruby Rose was nearly paralyzed doing a stunt, as a result of herniated discs in her neck, and had to undergo emergency surgery and went so far as to post a video of her spinal surgery on Instagram.
Rachel Skarsten has already portrayed a DC Comics character. She appeared as young Dinah Redmond (née Lance) on Birds of Prey (2002), daughter of the original Black Canary. In the series she would team with Batgirl (Barbara Gordon) and Huntress (Helena Kyle - the daughter of Batman and Catwoman) in a Gotham without a Batman.
The concept of Batman leaving Gotham and Batwoman protecting the city in his absence, which received some criticism, was part of the story of "52", where Kate Kane debuted. Also the Birds of Prey (2002) series had the same premise of Batman's absence and a female relative protecting Gotham in his place.