Jayne made her televised WWE debut on the September 23, 2020 episode of NXT, during which she competed in a number one contender's battle royal won by Candice LeRae. On February 24, 2021, she signed with WWE. She made her debut on the July 20 episode of NXT, where she lost against Franky Monet.
On the debut episode of NXT 2.0 on September 14, Jayne and Gigi Dolin faced Kayden Carter and Kacy Catanzaro in a tag team match, which ended in no contest after Mandy Rose interfered, during which she debuted a new dark-haired look, and they subsequently wrestled Carter, Catanzaro and Sarray in a six-woman tag team match, in which Rose, Dolin and Jayne emerged victorious. She quickly joined the women's stable Toxic Attraction led by Mandy Rose in 2021, thus establishing herself as a heel in the process. During the September 28 episode of NXT 2.0, the group was represented in their first in-ring match by Gigi Dolin and Jayne, in an NXT Women's Tag Team Championship match won by Io Shirai and Zoey Stark. At NXT Halloween Havoc, Dolin and Jayne defeated Shirai and Stark, and Indi Hartwell and Persia Pirotta in a Scareway to Hell ladder triple threat tag team match for the NXT Women's Tag Team Championship, marking the first championships for both Dolin and Jayne in the company.
On the November 16 episode of NXT 2.0, Jayne joined Gigi Dolin, Mandy Rose and Dakota Kai in a WarGames match at NXT WarGames to face Raquel Gonzalez, Kay Lee Ray, Cora Jade and Io Shirai. At the event, Toxic Attraction and Dakota Kai were defeated by Team Raquel. At NXT Vengeance Day, Gigi and Jacy retained their NXT Women's Tag Team Championships against Indi Hartwell and Persia Pirotta. On the NXT Stand and Deliver kickoff, Gigi and Jacy lost the NXT Women's Tag Team Championship to Dakota Kai and Raquel González with help from Wendy Choo's inteference, ending their reign at 158 days. However, they regained the titles with the help of Mandy Rose's distraction three days later on NXT 2.0. At NXT The Great American Bash on July 5, Gigi and Jacy lost the NXT Women's Tag Team Championship to Roxanne Perez and Cora Jade. After the titles were vacated, Gigi and Jacy participated in a fatal four-way elimination match on the August 2 episode of NXT 2.0, against Ivy Nile and Tatum Paxley, Yulisa Leon and Valentina Feroz, and Katana Chance and Kayden Carter. Gigi and Jacy were part of the final two teams in the match but eventually lost to Katana and Kayden. On the August 19 episode of SmackDown, Dolin made her main roster debut alongside Jacy Jayne as participants in the WWE Women's Tag Team Championship Tournament. They would win the first match, but were forced out of the tournament due to an injury suffered by Dolin. Dolin and Jayne made their return to SmackDown in a losing effort against new WWE Women's Tag Team Champions Aliyah and Raquel Rodriguez.
On the February 7, 2023 edition of NXT, during a Ding Dong, Hello! segment hosted by Bayley, Jayne turned on Dolin, ending Toxic Attraction. Jayne faced Dolin at NXT Roadblock on March 7, with Dolin winning the match. The former best friends went on to face each other again on May 2, where Jayne pinned Dolin. Their feud finally culminated on the May 30 episode of NXT, where Dolin defeated Jayne in a weaponized steel cage match.
On the August 15 episode of NXT, Jayne defeated Chase University's Thea Hail after Hail was distracted by her stablemates Andre Chase and Duke Hudson. Backstage after the match, Jayne gave praise to Hail and subsequently became a mentor to Hail, turning face for the first time since 2021, with Jayne eventually joining Chase University. On night two of NXT Halloween Havoc, Hail and Jayne failed to win WWE Women's Tag Team Championships from Chelsea Green and Piper Niven after Chase refused to allow Jayne to use the title belt against Green. In December 2023, Chase University started a storyline where it was revealed that the University was in heavy debt after Chase gambled away all their funds. On the January 30, 2024 episode of NXT, Jayne announced that she had created the "2024 Ladies of Chase U" calendar to be launched at NXT Vengeance Day and that the projected sales would save Chase University. Chase thanked Jayne and officially accepted her into the stable. Around the same time, Jayne took on a new protégé, Jazmyn Nyx, who would help Jayne win matches by cheating, which Hail refused to do. On the March 12 edition of NXT, after Hail and Fallon Henley lost a tag team match, an emotional Hail disavowed her friendship with Jayne and declared she was returning to the "old Thea Hail". On the following week of NXT, Jayne turned on Chase University and cost Riley Osborne the NXT Heritage Cup match against The No Quarter Catch Crew's Drew Gulak, turning both women heel in the process.
On April 2, a six-woman tag team match was made official for NXT Stand and Deliver with Jayne, Kiana James and Izzi Dame facing Thea Hail, Fallon Henley and Kelani Jordan, where Jayne's team lost the match. On the April 16 episode of NXT, Jayne and Nyx assisted Tatum Paxley in defeating Hail. A match between Jayne and Hail was then made official for week two of Spring Breakin' on April 30, where Jayne lost. Shortly thereafter, Jayne suffered a broken nose and had to undergo surgery. She made her return on the June 4 episode of NXT, sporting a face mask for her broken nose. On the July 9 episode of NXT, Jayne and Nyx formed an alliance with Fallon Henley, who took issue with rookies getting more opportunities in NXT (with Nyx given an exception by Jayne and Henley despite being a rookie herself) and eventually calling themselves Fatal Influence. The trio teamed up for the first time during week one of The Great American Bash on July 30, where they defeated Karmen Petrovic, Lola Vice and Sol Ruca in a six-woman tag team match. At NXT Halloween Havoc on October 27, Kelani Jordan faced Fatal Influence in a gauntlet match for the NXT Women's North American Championship. Jayne was the second person in the gauntlet and assisted Henley to defeat Jordan to win the title. Fatal Influence would soon begin feuding with Tatum Paxley, Shotzi and Jayne's former tag team partner and former friend Gigi Dolin, with the two teams facing each other at NXT New Year's Evil, with Fatal Influence coming out on the losing end.