|'Relationship'||Jimmy Neutron (The entire series)|
|'Family'||Mr. Vortex (Dad), Sasha Vortex (Mom), Susie Vortex (Aunt), Humphrey the Dog (Pet)|
|'Likes'||Winning, getting good grades, Babies, having power, and being admired|
|'Dislikes'||Jimmy Neutron(Hides her true feelings by pretending to dislike him), Betty Quinlan, Sheen Estevez (formerly), Carl Wheezer(formerly), losing, April and changing diapers|
Cynthia Aurora "Cindy" Vortex is Jimmy's simultaneous rival and romantic interest. She is considered one of the main characters and she helps her friends out on their adventures many times.
Cindy is basically the anti-dumb blonde role. She is a very prideful, intelligent, and competitive character, and she was shown with these personality traits throughout the series. She is shown to be good friends with Libby Folfax.
Little is known about Cindy's life before the events of "Jimmy Neutron: Boy Genius".
It is known that she moved to Retroville and initially found herself the most respected and most intelligent person in her class at school, a position in which she reveled. She also began a friendship with peers, such as Libby.
Jimmy took her "smartest person in Retroville" title when he moved into the house across the street from her whereupon Cindy, now second runner up, began a rivalry with him. She formerly began frequently attacks his intelligence by teasing him, playing pranks on him, and by criticizing his every mistake, although most likely she only does this to mask her love for Jimmy. She is frequently helped by her best friend and ally, Libby. Her home life is rarely shown and her parents are only minor characters in the show. However some of the statements she makes during "Stranded" seems to suggest that she is not very happy at home.
She is a member of the group of five, along with Libby, Carl, Sheen, and Jimmy, who usually go on his adventures with him. She began developing a deep friendship with these five, despite being the most aggressive and critical person in the group.
In the movie, Cindy wore a pink button up shirt with black pants and pink sneakers. Also, instead of wearing her hair in her usual single ponytail, she wore pigtails with her trademark bang. When the TV series began, Cindy's entire look changed. She began wearing a single ponytail in her hair as well as changing her entire wardrobe. She now wears a green-striped halter shirt with khaki pants and white sneakers. She also wears poka dot panties as shown in "When Pants Attack".
Cindy has, indeed, shown obvious but reluctant friendship with Jimmy Neutron, whom she calls numerous nicknames, the most common of which being "Nerdtron." In the episode Stranded, Jimmy was shocked when she called him by his real name, believing she never knew it.
In the first season, she "crushes" on Nick Dean. In the second season, nicknamed "The Relationship Season," their relationship begins to show through much more. Throughout the second season, the viewer observes a blossoming albeit odd romance between Jimmy and Cindy. Their relationship finally becomes acknowledged by Jimmy and Cindy in the middle of the third season, when they equivocally (kind of, but not quite) admit their true feelings while stranded on an uncharted island in the thirty minute episode, Stranded. During the hour long special The League of Villains, Cindy makes several attempts to confess her love to Jimmy, only to be inadvertently interrupted by someone or something and ignored by Jimmy. It is also hinted that Jimmy has feelings for Cindy in Billion Dollar Boy when he agrees to accompany Eustace after Cindy shows that she kind of likes Eustace. Later, however, that interest turns to dislike after Eustace says that he has no further use for "Neutron's squeeze". Season three is rich with what Jimmy and Cindy (or Jindy) fans refer to as "J/C moments." In "My Big Fat Spy Wedding," she saw Jimmy in a tux and got hearts in her eyes.
Cindy also knows when things are going too far. Increasingly, she is forced to authentic admission that Jimmy can indeed do some cool things and have cool adventures. During season three, as she starts to come to terms with her feelings for Jimmy, she mellows out, slowly dropping their rivalry and picking on Jimmy and his friends less and less. Instead, she begins to make several attempts to get Jimmy's attention.
In the crossover with The Fairly OddParents, "Jimmy Timmy Power Hour", Cindy develops a small crush on Timmy who everyone else thinks is Jimmy with a smaller head. In the second crossover special, Jimmy starts to get jealous. However her feelings for Timmy, while more open, definitely aren't as strong as her love for Jimmy. In the third crossover, Jimmy and Timmy both ignored her and their friends.
Her rivalry with Jimmy is still shown in the third, no canon crossover. In the final scene, she took advantage of Jimmy's lost intellect to command him to repeat that she was smarter than him.
In the final episode, Jimmy and Cindy finally kiss.
- During "The Retroville 9", they briefly share a victory hug.
- At the end of "I Dream of Jimmy", Jimmy kisses dream Cindy in order to get Carl to realize it was a dream, however he said it was "a horrible and desperate thing [he] had to do."
- In "Return of the Nanobots", when everyone reappears, Jimmy catches Cindy, since she appeared in the sky. They look at each other and smile before he drops her.
- During "Stranded", they inadvertadly reveal their feelings for each other, and almost kiss.
- In "The N-Men", Cindy tries to tell Jimmy her feelings but faints before she gets a chance to.
- In the hour special, "The League of Villains", Cindy constantly tries to tell Jimmy her feelings only to be interrupted each time.
- In "The Tomorrow Boys", it is shown that they get married.
- In "Lady Sings the News", they interact romantically several times, specifically at the end when Jimmy kisses her and their new relationship is left to the imagination of the viewers.
- In "Trading Faces", Cindy stated that one of them imagined them holding hands while walking down a country meadow and kissing.
- In "King of Mars" Cindy tries to flirt with Jimmy but got angry when he kept on ignoring her (later revealed he was doing so because her beauty kept distracting him).
- In "Win, Lose and Kaboom" Cindy and Jimmy almost kiss, with Cindy nervously asking him how the Gorlockan Seal of Trust worked.
In the episode "Send in the Clones", the romantic clone of Jimmy went to Cindy's house to deliver some articles. Cindy (shortly) was attracted to him, but lied saying he threatened her. This is only one of many obvious indications of Cindy's budding romantic feelings towards Jimmy.
Libby is Cindy's best friend, and one of the few characters that she has shown little to no anger or aggression towards during the series. Their friendship began before the movie or the series, as they are clearly very close even during the movie. Libby is also the only character that Cindy has been seen frequently confiding in.
Libby also shows a deep understanding of Cindy's actions and feelings, shown on multiple occasions. Libby also knows that Cindy has a crush on Jimmy. This says very much about the strength of their friendship, as Cindy is a very guarded and argumentative person, who obviously doesn't enjoy allowing many people to become close to her.
This is a very strong friendship in the series, one of the strongest along with the friendship between Jimmy, Carl, and Sheen.
Cindy's "friendship" with Carl and Sheen is obviously strained. She is shown to be annoyed by both of them, while they think that she is violent and mean. Cindy is constantly teasing and picking on the two of them, especially when Jimmy is present with them.
Despite their dislike for each other, the three are drawn together by Jimmy, who befriends Carl and Sheen, and eventually Cindy, and Libby, who is friends with Jimmy, Sheen, Cindy and Carl. The group is formed because of this, and the five become friends, including Cindy, Carl, and Sheen.
Little is known about Cindy's family life, which is what makes it so questionable. Her father is hardly ever seen on screen having little or no speaking lines and only appears in "Make Room for Daddy-O", while her mother seems to be pushy and prideful. Some of Cindy's statements in the episode "Stranded" also bring her happiness at home into question.
She's primarily disliked her because Jimmy has fallen head over heels for her. In the episode "Vanishing Act," Betty pulls Cindy aside to confront her about the Cindy/Jimmy thing. Cindy instantly questions what she is talking about, nervously repeating herself and denying that anything is going on between the two of them. Betty merely chuckles at this and tells Cindy to stay out of her face and that Jimmy is "all yours." Cindy visibly smiles and squeals the word "Yes!".
Cindy is shown to dislike April because of Jimmy's affections for her. After she catches April kissing Jimmy, which in Gorlock culture was a symbol of trust. She misinterprets it as Jimmy swapping "alien spit" with April only then to claim that she doesn't care at all. April then assumes she is Jimmy's mate, causing both Jimmy and Cindy to gag at the statement. At the end of the special, just when Jimmy and Cindy are about to kiss, a space rock hurtles down from the sky to land just outside of the Candy Bar. Both race outside to find that it is a message from April.
Cindy was born in June 5.