Kaywinnit Lee "Kaylee" Frye is a fictional character from the short-lived television series Firefly and the movie Serenity, portrayed by Jewel Staite. Kaylee has exceptional mechanical aptitude, despite her lack of formal training, and serves as ship's mechanic to Serenity. Kaylee is considered by the crew to be exceptionally sweet and chipper, the type who maintains a bright attitude even when others are feeling low.

CHARACTER HISTORY
Kaylee joined the spaceship Serenity when its captain, Malcolm Reynolds, found her having sex with his own mechanic, Bester, in the engine room of Serenity. While Bester informed Mal that the ship could not be fixed, Kaylee quickly repaired Serenity and Mal immediately offered her Bester's job.

In the pilot episode, Kaylee is shot by the Alliance agent Lawrence Dobson. Simon Tam uses her injury as a bargaining chip to be allowed to remain on Serenity with his sister, River. While Kaylee is being tended to by Simon after being shot by Dobson, Jayne Cobb is huddled on the catwalk outside of the infirmary. Earlier in this episode Jayne had been banished from the dinner table for making lewd comments about her obvious attraction to Simon, thus humiliating her in front of Simon while leaving Simon himself very embarrassed. And yet, his obvious concern emphasizes her importance to him and implies how deeply the other members of the crew care about her - although Jayne would still embarrass her in later episodes by making fun of her attraction to Simon, usually right in front of Simon.

Kaylee has shown an affinity for strawberries. As part of payment for being allowed passage on Serenity, Shepherd Book offers her a small box of strawberries, which she eagerly accepts. In a later episode, when she accompanies Malcolm Reynolds to a ball, she immediately hones in on the bowl of strawberries on the buffet table.

Despite her mechanical aptitude which allows Kaylee to fix just about anything, she has a desire for girlish things and is annoyed when Mal does not see that she is a woman as well as a mechanic. Although most notable in the episode "Shindig", this recurs throughout the series.

On the rare occasion that her ability as a mechanic fails her, she tends to lose her sunny disposition, as happened in "Out of Gas". Kaylee tends to personify Serenity, talking about her as if the ship were a sentient creature, and Kaylee takes insults to the ship personally.

In the movie Serenity, Simon Tam confesses his feelings for her, which she reciprocates. The ending implies strongly that they are now a sexually active couple; a scantily-clad Kaylee and a shirtless Simon kiss each other passionately, then sink to the engine room floor (falling out of frame in the process), with River peeking in voyeuristically from an overhead hatch.

Simon - Kaylee develops a romantic attraction to Simon which remains unconsummated during the run of the series, even though it is clear that Simon's feelings are mutual. It is often his 'proper' attitude that prevents the two of them from ever engaging in a more meaningful relationship, or his dedication to protecting his sister. This is not helped by that fact that he sometimes makes comments that hurt Kaylee's feelings, insulting the lifestyle of the crew, Serenity, and even herself, though he never intentionally means to insult her. Simon himself almost never gets mad at Kaylee, the only time being Objects in Space where Kaylee revealed River's disturbing expert use of a handgun, which placed a dark cloud over River in the eyes of the others, which in turn angered Simon, although he was able to control it.

Mal - The overall relationship between Mal and Kaylee closely resembles that of a brother and sister. In the pilot episode, he refers to her as "Xiao Mei Mei" meaning "Little Younger Sister" in Mandarin.

Inara - Kaylee enjoys spending time with Inara, who indulges Kaylee in doing "girly" things, from shopping to combing her hair, like a best friend or a surrogate older sister to a younger sister. Inara also offers Kaylee advice on her love life, i.e., how to deal with Simon or get Simon to notice her.

River - River and Kaylee enjoy playing together and relate somewhat similar to teenage friends talking about boyfriends and past experiences. A scene where River jokingly steals Kaylee's apple results in a chase through Serenity and Kaylee claiming back the apple then stating "no power in the 'verse can stop me". Later on in the episode River repeats the statement after killing three men and saving Kaylee. Kaylee is understandably somewhat distressed by the incident.