|Relatives||Unnamed mother, father, and little brother|
|Cause of Death||Brain tumor|
|First Appearance||The Fault in Our Stars|
Caroline Mathers is a background character in The Fault in Our Stars. She was another cancer victim in the book and died of a brain tumor while dating Augustus Waters. Caroline is first introduced when Hazel and Augustus are talking about their first kisses. When Hazel asks what happened to her, Augustus said, "She is no longer suffering from personhood." In Amsterdam, he reveals she died from brain cancer. Later, when Hazel looks Caroline up, she finds pictures and comments of Caroline.
Caroline Mathers was only noted in the books during the time she was diagnosed with a brain tumor. She was potrayed as a moody, blunt and miserable person whose crude personality was due to the "asshole tumor", as said by Augustus. She, at one point, make fun of Augustus's missing leg. Such as, "Gus has great legs. I mean, leg." and then laughing like a maniac. Though, he does claim that he never knew if the behavior was her personality or the tumor. During the later stages of her relationship with Augustus her attitude was said to have gotten worse. She was described by Augustus as "not having a filter between her brain and her mouth".
While Hazel looks through her last pictures online, she describes Caroline as having a round face, round nose, the same overall body shape as herself with dark brown eyes and her complexion was Italian, wide hipped, curvy with long dead straight black hair falling in front of her face.
She also says that she and Caroline look quite alike in their "cancer states", which is why Augustus was staring at her during the Support Group meeting in which he and Hazel first meet in the beginning of the book.