The actor said in a series of Instagram Story posts that she had "complications" after a procedure and that it took "hours to find a hospital" that would take her.
The "God Friended Me" star replaces Ruby Rose, who departed the CW series after one season.
The actor shared a cryptic Instagram post about leaving the CW series after one season.
The actor played the first openly queer superhero in a live-action series title role.
Ruby Rose plays Gotham City's LGBTQ crime-fighter on the CW series.
"Well that was fun," the "Batwoman" star quipped on Instagram.
The CW series — the first superhero live-action TV series to feature an LGBTQ title character — is set to debut in the fall.
The CW announced it was picking up the show, making Ruby Rose's character the first openly queer superhero in the title role of a live-action series.
The superhero is an "out lesbian and trained street fighter" who might be getting her own series.
"The Meg" actor also deactivated public comments on her Instagram account.