On October 15, 2019, it was reported that Blackheart had signed with WWE and would report to the WWE Performance Center. Blackheart made her debut on a live NXT house show on December 5, 2019, losing to Chelsea Green. She made her television debut on NXT on December 18, 2019 against Bianca Belair.
She entered the women's Royal Rumble match at number 26 and lasted for 7 minutes and 27 seconds, before being eliminated by Shayna Baszler. Additionally, she was attacked backstage by Deonna Purrazzo after the match, resulting in a match between the two on the January 29, 2020 episode, where Blackheart defeated Purrazzo by hitting the Senton Splash. On the July 15, 2020 episode of NXT, Blackheart lost against Indi Hartwell after interference from Aliyah and Robert Stone. This led to Blackheart running over Stone with her toy tank in the following weeks of NXT. On the September 16 episode of NXT, Blackheart challenged NXT Women's Champion Io Shirai in a non-title match, but was unsuccessful. At NXT Halloween Havoc on October 28, she served as the host during that episode, getting involved in the Tables, Ladders and Scares match for the NXT Women's Championship. The following week, she lost to Toni Storm when she was distracted by Candice LeRae, who was with her tank, and destroyed it after the match, leaving Blackheart horrified and devastated. The following week, she cut a furious promo swearing revenge on LeRae, and Blackheart then attacked LeRae after her match with Storm, but this wasn't successful as LeRae was assisted by Indi Hartwell, allowing LeRae to finish off Blackheart with her Wicked Stepsister finisher. Blackheart then began to assemble a team consisting of Rhea Ripley, Io Shirai and Ember Moon for the NXT TakeOver: WarGames pay-per-view, where her team faced off against LeRae, Storm, Raquel Gonzalez and Dakota Kai in a WarGames match, which Team Shotzi lost. On the Match 10, 2021 episode of NXT , Blackheart and her tag team partner, Ember Moon, defeated Kai and González to win the NXT Women's Tag Team Championship, her first title in NXT. At NXT TakeOver: Stand and Deliver, they successfully retained the titles against The Way (Candice LeRae and Indi Hartwell). On the May 4 episode of NXT, Blackheart and Moon dropped the titles to The Way in a street fight, ending their reign at 55 days.
On the July 9 episode of SmackDown, Blackheart, now under the shortened ring name Shotzi, debuted alongside Tegan Nox to defeat the WWE Women's Tag Team Champions Natalya and Tamina in a non-title match. The team was disbanded when, as part of the 2021 Draft, Nox was drafted to the Raw brand while Shotzi remained on the SmackDown brand. On the October 29 episode of SmackDown, after her match with SmackDown Women's Champion Charlotte Flair in a championship contender's match, Shotzi attacked Sasha Banks, who was at ringside, turning heel. She participated in the five-on-five Survivor Series elimination match at Survivor Series, but was eliminated by Bianca Belair. She participated in the Royal Rumble match at the namesake event on January 19, 2022, entering at number twenty-nine, but was eliminated by the returning Ronda Rousey. On the June 24 episode of SmackDown, she defeated Tamina to qualify for the Money in the Bank ladder match, where she was unsuccessful in winning the match. On the September 16 episode of SmackDown, she saved Raquel Rodriguez from an attack by Damage Control (Bayley, Dakota Kai and Iyo Sky), turning face in the process. On the October 21 episode of SmackDown, Raquel and Shotzi challenged the WWE Women's Tag Team Champions Damage Control (Dakota Kai and Iyo Sky) for their titles; however, were unsuccessful after Bayley distracted Shotzi. The following day, she served as the host for NXT Halloween Havoc alongside Quincy Elliott, and attacking Lash Legend after she interrupted them. On the November 11 episode of SmackDown, Shotzi won a six-pack challenge, earning a SmackDown Women’s Championship match against Ronda Rousey on November 26 at Survivor Series.
In the summer of 2023, Shotzi began feuding with Damage Control (now consisting of a duo of Bayley and Iyo Sky, due to Dakota Kai being injured). Following an attack by the group, Shotzi would have some of her hair cut off by Bayley. The following week on SmackDown, Shotzi would shave her entire head as a message to Bayley. In November at Survivor Series: WarGames, Shotzi, along with Bianca Belair, Charlotte Flair and Becky Lynch, defeated Damage Control (Bayley, Asuka, Iyo Sky and Kairi Sane) in a WarGames match. During the February 20, 2024 episode of NXT, Shotzi suffered a knee injury against NXT Women's Champion Lyra Valkyria.