Its a character reference from: https://www.mangago.zone/read-manga/miss_not_so_sidekick/
~Spoilers ahead (explaining Ibeline syndrome)
Basically Ibeline is character that never experienced negative emotions and was always praised/loved. Thus, she develops the warped idea that she is entitled to people's admiration. When the MLs lose interest in her (and pay attention to the FL), she puts up this act to regain the MLs' attention- sometimes forcing the FL into awkward situations. I don't think she targeted the FL specifically, but she did leave a bad taste for readers. (Mostly because she was such an attention whore). *Note that this is revealed at the very end of the novel.
Other than that, it's a really good manga- lots of humor and a wacky art style

Either she has the Ibeline syndrome, or somehow a fucked up version of herself after repeating the same storyline too many times.
I don't think she is a reincarnator/transmigrator but I am leaning on that Ibeline syndrome theory