Kaylie is described by Payson as the 'one who got everything.' She is described as beautiful with olive skin, brown eyes and chesnut brown hair with a winning smile. Her mother, Ronnie, was a one hit wonder in the 1980s and 1990s, and her father, Alex, was a successful baseball player, who is revealed to have an anger issue. Kaylie disagrees with and breaks one of the gym's main rules: that each girl training should not be romantically involved with anyone. Kaylie is secretly dating Carter, a fellow gymnast at The Rock, although for several episodes she is unaware that Carter had slept with Lauren, Kaylie's best friend. Kaylie discovers her mother's affair with Marty, The Rock's previous coach and upon confronting her mother, it is revealed that Ronnie knows about Kaylie and Carter as well. She is ultimately best friends with Payson and Lauren, but has a good relationship with Emily as well. Later in the series, Carter gives her a necklace from his late mom, who said to give it to the girl that he wants to spend the rest of his life with. However, she returns the necklace to Carter during Nationals, and breaks it off with him after she found out about Carter and Lauren. She edges out Kelly Parker, becoming the Nationals Champion. Kaylie and Carter later kiss, but the reconciliation is ruined when Kaylie discovers that Lauren has been letting Carter live in her house and still has feelings for him. In the episode "Are we family" Kaylie decides not to compete against China even though the rock really needs her, but her dad Alex encourages her to help her team win against China. Kaylie decides to compete and is the first person to win against China's top gymnast. After finding out that Carter cheated, Kaylie break up with him. Kaylie kissed Austin at his house when she is upset. She wants to add a triple arabian to her routine even though Gengi Cho is the only gymnast able to accomplish it. When Sasha tells her that she doesn't have the right body type to perform the move she begins exercising vigorously and trying to lose weight. Kelly Parker is the first to notice how skinny she is but is told by Ellen Beals that Kaylie is a dedicated gymnast. She placed first in the final ten of the National's Team and will continue on training for one of the six spots on the World's Team.
- Love triangle between Carter, Lauren and herself.
Personality and appearanceEdit
Kaylie is outgoing and basically just wants to be a regular teenager. She can be selfish but in the end she feels bad about acting mean. Kaylie is very stubborn and sticks to what she wants and believes in. Kaylie is the "girly-girl" of the group.
Kaylie has a very light brown skin tone and is dark haired.
- Ronnie Cruz (played by Rosa Blasi): Ronnie is Leo and Kaylie's mother. Ronnie had an affair with Marty, the former coach of The Rock. Ronnie was a model and singer who went platinum in the early '80's to late '90s. Kaylie finally forces her mother to admit to her affair, which causes Alex to move out and file for divorce, despite Kaylie's pleas. She and Alex promised Kaylie they would wait six months before divorcing in hopes of getting them back together. She is also Kaylie's new Co-Manager, handling her press.
- Alex Cruz (played by Jason Manuel Olazabal): Alex is Leo and Kaylie's father, a former baseball star with an anger issue. Alex pushes Kaylie to the maximum level until she finally fires him as her manager so that he can be her father. He hates Carter for being involved with Kaylie. When he discovers that his wife was having an affair with Marty, Alex moves out and eventually files for divorce from Ronnie. He along with Ronnie promised Kaylie to wait six months before divorcing. He is also Kaylie's new Co-Manager, handling her training. Kalyie hopes this will help them get back together.
- Leo Cruz (played by Marcus Coloma): Leo is Kaylie's older brother. Leo is in college, but is now moving back to Boulder to help Sasha with some coaching at The Rock. Leo is good friends with Emily. He has shown chemistry and feelings towards Emily, but was shoved in the background upon Damon's arrival. He shows great care towards his sister, hitting Carter once he is notified of Carter's affair with Lauren. Leo is smart and a decent athlete, but was never as good at gymnastics as his sister, Kaylie.