Bonnie and Kim have been going to school together since at least middle school. While it is unknown how long she has actually known Kim, she knew her long enough prior to when Kim first tried out for cheerleading in middle school to have given her the nickname "Tin Teeth", due to Kim having braces at the time. She knew Ron almost at least as long as Kim knew him, as Bonnie had been calling him cruel names from Kindergarten to 12th grade.
Bonnie usually comes off as very mean, rude, and snobby with a dismissive, cold attitude, and a superiority complex toward Kim, Ron Stoppable, their friends, and people in general, whom she considers being beneath her. But while bonded to Kim's hip for a short time, it was strongly implied that Bonnie's sour disposition stems from her two older sisters, Connie and Lonnie, always being mean to her.
She generally avoids hard work. Although she did once put a lot of effort into usurping Kim as the Middleton High cheerleading captain while Kim was distracted with a mission. However, after Bonnie did gain the position, with the surprise help of Kim adding her vote and support to Bonnie, Kim explained that the hard work was only just beginning. After hearing that and realizing the responsibilities of actually being the captain of the squad, Bonnie started having second thoughts about it and presumably gave the position back to Kim sometime within two weeks or so (Ron figured that Bonnie would only last a month while Kim figured two weeks at the most).
Bonnie is also not above cheating to achieve her goals, such as rigging her senior year Homecoming-vote to become Queen, a result which could only enhance her standing on the proverbial "food chain", if not take her to the top.
Bonnie is a tan-skinned brunette of average height. She has shoulder-length brown hair in a shag cut, teal eyes, a slender but curvaceous figure, and may be around 105-lb as stated by Kim when she and Bonnie were bonded together, due to the effects of an invention by Professor Dementor. However, that could just have been an estimation on Kim's part.
Bonnie is almost Kim's physical match, although her skills are geared more towards dancing and gymnastics and she has virtually no combat skills. She also has a talent for pushing all the right buttons, and for faking sincerity at opportune times. She bragged to Kim and Ron that she had taken twelve "intensive" years of ballet when she had signed up for the Middleton High School talent show.
Bonnie's also shown to be an excellent driver, having been the only one in her Driver's Ed class to have actually passed on the first try.
Role in the series
Bonnie is Kim's rival at Middleton High School and a fellow member of the school's cheerleading team. She is very much concerned about the proverbial "food chain" at their high school and angled to keep her position on it by saving seats at lunch for the even more popular senior, Amelia, and by dating Brick Flagg, the star quarterback of the Middleton High football team as that was considered a status symbol. Whenever an opportunity of humiliating and/or upstaging Kim presented itself, Bonnie was almost always willing to go through with it. During the series, she (often unintentionally) followed Kim on her missions, one of which led her to meet Señor Senior, Junior, whom she falls in love with.
In the series finale, Bonnie does not graduate with the other seniors for missing school hours and is forced to go to summer school in order graduate, much to Bonnie's dismay. At the senior graduation party, Bonnie is bitterly studying summer school unable to participate in the festivities. However, her spirits are lifted when Junior shows up at the party to cheer her up as the couple decides to continue their relationship.
Mrs. Rockwaller appears to be enthusiastic and kind-hearted, but is shown to be a source of consternation and embarrassment for Bonnie.
Bonnie's only known siblings, the girls enjoy being mean to Bonnie by teasing and belittling her. According to them, Connie "got all the brains", Lonnie "got all the looks", and Bonnie "got the rest".
The rivalry/conflict between Kim and Bonnie was seen and mentioned through almost the entire series. Bonnie felt challenged by Kim's general popularity as well as her being the school cheerleading captain, the latter of which Bonnie coveted and managed to gain before eventually giving it back to Kim. Since then, Bonnie was never nearly as vocal about replacing Kim as the captain. However, she still angled to have prominent positions in routines, ever ready to step in whenever Kim might miss her mark in a layout.
Bonnie once bonded with Kim's younger brothers, Jim and Tim, apparently for their potential to embarrass their sister in public. However the tweebs were themselves just hanging out with Bonnie to bug Kim, and they apparently did not like Bonnie that much, as seen when they "repaired" her car but then remotely disassembled it when she blew off their contract.
There are a few times when Kim and Bonnie appear to get along fairly well.
Bonnie was rather cold to Ron. Most of the series, she referred to him as a "loser", even to his face. While Ron was a millionaire she kissed up to him and was part of his posse to reap the benefits of his freely-flowing new found wealth. Though she did bluntly tell him exactly that and never pretended her interest was genuine. After it was gone, she returned to treating him coldly. Apparently, she wasn't as mean towards Ron when she was younger but stepped up her level of disdain for him as Ron mentioned she had been mean and abusive to him since middle school.
During her senior Homecoming, Bonnie rigged the election with the aid of fellow senior Ron Reiger to get herself voted as queen; leaving her to attach herself to Homecoming King, Ron, even kissing him to keep him from explaining what his true feelings were and with whom they lay. Realizing what she was doing and with whom, she broke down and admitted it was all due to being dumped by Brick, and that Ron was just the rebound.
Brick was Bonnie's on-again/off-again boyfriend for most of the second and third seasons of the show, until after he graduated and said he could no longer stand her, having dumped her presumably by phone from college.
Bonnie and Junior first met and started dating when she tagged along on a mission with Kim and Ron where Junior had seemingly kidnapped a world-renowned computer-technician. It was essentially love at first sight and they remain together for the rest of the series.
After Bonnie was forced to go to summer school in order graduate from high school, Junior cheers her up by saying that he will be there with her in spirit, after saying that his actual self will be lounging by his pool.
- In the future segment of A Sitch in Time, an older Bonnie was a teacher at the Disciplinary Center, and one of her students was an older Brick Flagg.
- Bonnie retains her name like the rest of Shego's higher up staff. However, unlike Drakken and Monkey Fist, Bonnie does not have an obedience collar. This heavily implies she agrees with Shego's rule and enjoys her life.
- Bonnie gets embarrassed when her mother calls her Pumpkin and Bon Bon.
- Deep down Bonnie is jealous of Kim.
- It's unknown if Bonnie has any other siblings outside of Connie and Lonnie―her comment in Hidden Talent implies that she has other siblings outside of them, but it's also possible that she was just trying to distance herself form her sisters.
- It's also unknown who Connie, Lonnie and Bonnie's father is, as he's never been seen or mentioned and their mother's only seen once in person (and she appeared by herself).