Charlie Sue is a nickname attributed to the character Charlie Bradbury. As Charlie's appearances on the show began to expand, segments of the fandom began claiming she was becoming nothing more than a Mary Sue – an idealized character/author self-insert – creating the portmanteau "Charlie Sue." This view of Charlie came from various instances on the show regarding her characterization, and the fact her creator, Robbie Thompson, was the only writer to use the character in episodes (excluding the episode with her death). Examples included:
- Being told by Dick Roman she was too unique to be copied.
- Men and women instantly falling for her.
- Became a proficient hunter with little to no training and no mentor.
- Being an expert marksman without much explanation.
- Her "dark self" single handily winning the war for Oz.
- Sam needing Charlie to talk him through hacking information, despite Sam being a good hacker in his own right.
Although segments of the fandom have attributed Charlie's qualities as a "Mary Sue," many in the fandom simply saw the character as an example of strong female and LGBTQ representation, flawed as it may have been at points, but representation nonetheless.