Kiper was born in Brooklyn, New York. She started acting at the age of 19, appearing in several commercials and had cameo roles in a couple of TV shows. Her first major break was in the popular LA-based vampire TV show Angel, where she appeared in a single shot in the Season 4 episode Ground State as Gwen's assistant Nick. This garnered her a small, but pivotal role as Jess's girlfriend, Shane, on Gilmore Girls. She then proceeded to do different TV shows and films, most notable as Precious in Sex and Death 101, with Winona Ryder and Simon Baker.

Currently, Kiper lives with her dog, "Major P. Pants". She was once engaged to actor Tony Denman. She also plays drums and sings in a band called She Loves Betty White.

Kiper competed on the reality television show Survivor: Gabon, the seventeenth season of Survivor, which began airing on September 25, 2008. She was referred to throughout the season by the nickname "Sugar". The final episode of the season, broadcast on December 14, 2008, revealed that she finished third, behind winner Robert Crowley and second-place finisher Susie Smith, garnering no jury votes.

Survivor host Jeff Probst commented on Kiper, saying :"She is in an excellent spot to make it to the final vote. I'll give her credit. She has done a very good job of staying in this game and staying out of the way. She's survived a record number of days on Exile, she handled the power of the immunity idol beautifully, and she has earned her right to be in the final five."

Kiper found the Hidden Immunity Idol very soon after arriving on Exile Island, beating lawyer Dan Kay who got the same opportunity the previous episode, and she played it during Episode 12 in order to save fellow contestant Matty Whitmore, thus negating two votes cast against him and ensuring the elimination of athlete Crystal Cox. She ended the series in third place, losing to teacher Robert Crowley and hairdresser Susie Smith. She was also the second choice for the 'Sprint Survivor of the Season' award, losing again to winner Crowley.

Kiper was a contestant in the 20th season of Survivor, Survivor: Heroes vs. Villains. She was a member of the Heroes tribe. She was the first to be voted out, after being perceived as weak, and her emotions and flirtatious behavior irritating her tribemates.