Haley was conceived before her parents got married. So they eloped and told everyone that the pregnancy was a surprise. It was explained that Haley was very close with her mother when she was younger, but they grew apart once she hit adolescence. She constantly bickers with her parents and younger siblings, but does show to generally love and care about her whole family.
Haley is described by Claire in the "Pilot" as being very much like her when she was a teenager. So she tries to makes sure that her daughter won't make the same mistakes. Haley starts dating Dylan during the first episode, and he becomes her first boyfriend. She is concerned about her popularity at school which she contributes to her embarrassment of her parents. She is learning to drive and isn't very good (she once refused to pull over when being signed by a police car because she was afraid of cops), but later improved and got her license. She and Dylan have an off-again on-again relationship as they do for most of the show.
Dylan wins Haley back after performing a song outside her house on Valentine's Day. After receiving her SAT scores, Haley tells her family that she does not want to go to college because she believes it's a waste of time. But she later explains to Alex that she's scared about leaving high school since she's barely passing the 11th grade.
While vacationing with the family in Wyoming, Dylan proposes to Haley in front of her entire family. Claire immediately says no for her. Causing tension in their relationship since Haley believes that her mother won't let her make her own decisions. Dylan ends up going missing, but he's later found after getting a job as a ranch hand. So they break up once again. She is afraid that she won't be accepted into a college, but she is wait-listed by a college at the end of "Election Day". After months of waiting and finally accepting that she won't be accepted into a college, she decides to move in with Dylan after she graduates. Luke confesses though that he hid her acceptance letter (along with a lot of other mail) because he doesn't want her to go. After finding out that she is in fact going to college, she and Dylan decide to go to prom.
Haley finally goes to the college as shown in "Schooled". But a few episodes later, she goes off to college only to be kicked out for underage drinking and (accidental) battery of a police officer. She then moves back in with her family and starts having to deal with the pressure from her parents to attend community college, go to work and get her life together in general before she is able to re-apply at the college next semester.
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