She made her debut on the first episode of the weekly television program ECW, on June 13, 2006, becoming the youngest Diva on the WWE roster. Her character, an exhibitionist, was introduced performing a striptease for the crowd. The next week, while performing another striptease, Kelly was interrupted by her on-screen boyfriend, Mike Knox, who came to the stage and covered her with a towel before dragging her backstage. Her stripping became a weekly segment known as Kelly's Exposé and usually followed the same routine; Kelly would dance and strip until she was interrupted by Knox who was upset by her exhibitionism and showing off her body to others. Knox began forcing Kelly to accompany him to ringside so he could keep an eye on her, making her his de facto valet. As a result, she found herself involved in the feud developing between Mike Knox and partner Test with Tommy Dreamer and his partner The Sandman, including being inadvertently hit with a cane by Sandman when Knox used her as a shield. She made her ECW in-ring debut on the August 22, 2006 episode of ECW on Sci-Fi in a losing effort as part of a six-person mixed tag team match which saw herself, Knox, and Test lose to Dreamer, Sandman and Torrie Wilson, in what was the last match of the feud.
Following this feud, Kelly and Knox were moved into a storyline with CM Punk in September, in which Kelly was shown to have developed a liking for Punk and Knox was shown to be increasingly protective and jealous. During the next month, Kelly continuously flirted with Punk and was shown watching his matches from the crowd, until Knox stopped her. Subsequently, Kelly's character dressed as Punk for ECW's Halloween Costume Contest, enraging Knox and leading to a match between the two, during which Kelly cheered for Punk. At December to Dismember, Kelly and Knox took on the team of Ariel and Kevin Thorn in a mixed tag team match, during which Knox refused to tag in before abandoning Kelly, leaving her to be beaten badly by Ariel. On the following episode of ECW, Kelly defeated Ariel with a roll-up on her first ECW singles match, after which Knox made his way to the ring with flowers only to throw them in Kelly's face and perform his signature swinging reverse STO on her, ending their relationship and giving her a scripted injury—removing her from the program for six weeks.
She returned to television on January 16, 2007 and cut a promo announcing she was newly single and bringing back Kelly's Exposé. The following week, she joined forces with Layla and Brooke to form Extreme Exposé. The trio performed a weekly dance segment on ECW for the next several months, as a successor to Kelly's Exposé segment. In June 2007, The Miz was moved to the brand, prompting a storyline in which all three members of Extreme Exposé were attracted to him. When Kelly shifted her attentions towards Balls Mahoney, Layla, Brooke, and The Miz openly mocked her, and The Miz later prevented her from going on a date with Mahoney, stating that he owned her contract and would fire her if she did so. On November 1, Brooke was released from her WWE contract, and Extreme Exposé dissolved as a group, leaving Kelly and Layla to enter an ongoing rivalry with more active wrestling roles. On the October 29 episode of Raw, Kelly won a battle royal to earn a match against the WWE Women's Champion, Beth Phoenix. After the match however, Kelly was attacked by Phoenix and lost the subsequent match between the two the following week on Raw. Kelly continued to feud with Layla, and they were on opposite sides of a 10-Diva tag team match at Survivor Series, which Kelly's team won. In December, Layla formed an alliance with Victoria, which expanded to include Lena Yada in January 2008, and Kelly continued to feud with the trio. At WrestleMania XXIV, Kelly was a 'lumberjill' for the Divas' tag team lumberjill match. The following month, Kelly was part of the losing team in a five-on-five Divas match at the Backlash pay-per-view.
Following the completion of the 2008 WWE Draft, Kelly was moved to the Raw brand on July 7. Kelly had her debut match as part of the brand that night by teaming with Mickie James to defeat Layla and Jillian Hall. She quickly became involved in a feud with Beth Phoenix, facing her on multiple occasions in both singles and tag team matches with a variety of opponents, including Mickie James and Candice Michelle. During this time, Phoenix was aligned with Hall, and in late September Kelly transitioned into a feud with Hall. At the Survivor Series pay-per-view in November, Kelly was part of the victorious Raw Diva team which defeated the SmackDown Divas in a five-on-five elimination match. During the match, she eliminated Victoria, before being eliminated by Maryse. The following month at Armageddon, Kelly teamed with Maria, Michelle McCool and James in a winning effort against Hall, Maryse, Victoria and Natalya.
On April 5, 2009, Kelly competed in a Divas Battle Royal at WrestleMania XXV, but the match was won by Santina Marella. On the May 18 episode of Raw, Kelly won a battle royal by eliminating Beth Phoenix and Mickie James, to become the number one contender to the WWE Divas Championship. The following week, she challenged Maryse for the championship and won by disqualification, allowing Maryse to retain. Kelly lost a subsequent rematch by pinfall two weeks later on June 8. Three weeks later, she competed in a fatal four-way match to determine the number one contender, but the match was won by James. Throughout the remainder of mid-2009, Kelly unsuccessfully competed in several number one contender matches. At the Bragging Rights pay-per-view in October, Kelly, Gail Kim and Melina comprised Team Raw, but lost to Team SmackDown, consisting of Phoenix, Natalya and McCool. The following month at the Survivor Series pay-per-view, Kelly participated in a five-on-five elimination match, which her team won. She eliminated Layla before being eliminated by Phoenix.
In January 2010, Kelly participated in the tournament to determine a new Divas Champion, after Melina was forced to vacate the championship due to injury, but was eliminated by Alicia Fox in the first round. Throughout early 2010, Kelly was involved in several backstage segments with the guest hosts of Raw. At WrestleMania XXVI, Kelly teamed with Phoenix, Kim, James and Eve Torres in a losing effort to McCool, Layla, Maryse, Fox and Vickie Guerrero. The following night on Raw, the teams faced off in a rematch with the opposite result. The following week, Kelly took part in a 10-Diva Dress To Impress battle royal, to determine the number one contender for Maryse's Divas Championship, but the match was won by Torres.
During the 2010 WWE Draft on April 26, Kelly was drafted to the SmackDown brand. She made her debut on the April 30 episode of SmackDown by teaming with Beth Phoenix to defeat LayCool (Michelle McCool and Layla). She went on to feud with LayCool, gaining an ally in Tiffany. Over the next several weeks, Kelly and Tiffany faced LayCool in tag team matches, with LayCool winning on both occasions. On the June 4 episode of SmackDown, Kelly made her singles debut for the brand, defeating Rosa Mendes, despite being distracted by Layla and McCool. After defeating both Layla and McCool in singles matches, she received a Women's Championship match at the Money in the Bank pay-per-view in July, but was unsuccessful. On August 31, Kelly announced that she would be a mentor on season three of NXT, with Naomi as her rookie. Throughout the second half of 2010, Kelly continued to feud with LayCool, and gained an ally in Natalya in October. In November, Kelly's NXT rookie, Naomi was named runner-up to the winner, Kaitlyn during the season finale.
In December, Kelly started a storyline with Drew McIntyre who had developed a romantic interest in her. She rebuffed his advances on several occasions, stating he was too aggressive and vindictive. On January 30, 2011, at the Royal Rumble, Kelly prevented the Acting General Manager Vickie Guerrero from interfering in the World Heavyweight Championship match between Edge and Dolph Ziggler. On the following SmackDown, Kelly and Edge defeated LayCool and Ziggler in a two-on-three handicap match to retain Edge's World Heavyweight Championship. Following the match, Guerrero fired Kelly in storyline. At the Elimination Chamber pay-per-view later that month, Kelly was re-hired by SmackDown General Manager Teddy Long, and made her return by attacking Guerrero. She was stopped by LayCool, who were in turn stopped by Trish Stratus. On the following episode of SmackDown, Kelly gained revenge on Guerrero when Kelly and Edge defeated Guerrero and McIntyre in a mixed tag team match, causing Guerrero to be fired in storyline per the pre-match stipulation.
On April 26, Kelly was drafted back to the Raw brand as part of the 2011 supplemental draft. On May 22 at the Over the Limit pay-per-view, Kelly unsuccessfully challenged Brie Bella for the WWE Divas Championship. The following month, on the Power to the People special edition of Raw on June 20, Kelly won a vote by the fans to determine the challenger for the Divas Championship that night. Kelly went on to win her first WWE Divas Championship by defeating Bella. Her win later garnered her a Slammy Award for Divalicious Moment of the Year. At the Money in the Bank pay-per-view in July, Kelly made her first title defense, successfully defeating Bella in a rematch. On August 1, Phoenix won a battle royal to become the number one contender to Kelly's championship, and afterward attacked Kelly to provoke a feud. Kelly went on to successfully defend her championship against Phoenix at SummerSlam. Following SummerSlam, Kelly continued to feud with Phoenix, defeating her at Night of Champions, before dropping the championship to her at Hell in a Cell in October. In a rematch on the October 14 episode of SmackDown, Kelly lost once again. Kelly challenged Phoenix for the Divas Championship at Tables, Ladders & Chairs, but was unsuccessful.
In early 2012, Kelly participated in several tag team matches. At WrestleMania XXVIII in April, Kelly and Maria Menounos defeated Beth Phoenix and Eve in a tag team match. In June, WWE granted Kelly a period of time off, and she returned on Raw on August 6, defeating Eve in singles match. On September 28, Kelly was released from her contract.