Valkyria signed with WWE on January 20, 2020. However, Valkyrie competed in her first match on NXT UK on January 17, 2020, defeating Amale under the ring name Aoife Valkyrie. She then defeated Isla Dawn the next night on January 18, 2020, and defeated Amale again afterwards. On March 26, 2020, Valkyrie defeated Nina Samuels.
In February 2020, Valkyrie toured with the NXT brand for the first time, wrestling on two house shows in Florida. Valkyrie defeated Aliyah on February 14 in Tampa, followed by defeating Jessi Kamea, MJ Jenkins, and Taynara on February 15 in a six-woman tag team match at a Fort Pierce house show, where she teamed up with Mia Yim and Rita Reis.
Valkyrie made her return to television on the September 17, 2020 episode of NXT UK in a winning effort against Isla Dawn, and on October 29, 2020, she competed against Dani Luna, again in a winning effort. Valkyrie remained undefeated until April 29, 2021, when she lost to Meiko Satomura. She would lose again to Jinny on the July 29 episode of NXT UK due to interference from Joseph Conners; however, she would defeat Jinny four weeks later on the August 26 episode of NXT UK in a no disqualification match in which Conners was suspended in a shark cage.
On the November 29, 2022 episode of NXT, a vignette was shown teasing her debut under the new name of Lyra Valkyria. On December 13, Valkyria made her debut on NXT, defeating Amari Miller. On the March 21 episode of NXT, Lyra beat Ivy Nile to qualify for the ladder match for the NXT Women's Championship at NXT Stand and Deliver, though she was unsuccessful in winning the title at the event. On the May 9 episode of NXT, she beat Kiana James to advance to the semifinal of the tournament for the vacated NXT Women's Championship. On May 23, she defeated Cora Jade to advance to the final, facing Tiffany Stratton at NXT Battleground. At the event, Stratton would win the vacant title. On night one of NXT Halloween Havoc on October 24, Valkyria defeated Becky Lynch to win the NXT Women's Championship. On the November 21 episode of NXT, Valkyria successfully defended her title against Xia Li.
On January 2, 2024, at NXT New Year's Evil, Valkyria successfully defended her NXT Women's Championship against Blair Davenport. After their match, Lola Vice tried to cash in her Breakout Tournament contract, only to be stopped by Tatum Paxley, who had been obsessed with Valkyria since December 2023. At NXT Vengeance Day on February 4, Valkyria successfully retained the NXT Women's Championship against Roxanne Perez and Lola Vice, who cashed in her Breakout Tournament contract while the match was in progress to make the match a triple threat. On the February 20 episode of NXT, Valkyria defended the NXT Women's Championship against Shotzi. During the match, Shotzi suffered a torn ACL and Valkyria won by referee's decision. NXT General Manager Ava then announced an open challenge for the NXT Women's Championship match, which Lash Legend answered. Valkyria would successfully retain the title against Legend. At NXT Roadblock, Valkyria and Paxley faced The Kabuki Warriors (Asuka and Kairi Sane) for the WWE Women's Tag Team Championships as a reward from Valkyria to Paxley for the latter not interfering with the former's title matches in the previous week, but failed to win the titles after Valkyria inadvertently kicked Paxley. After the match, Perez attacked Valkyria and injured her arm. Valkyria returned and attacked Perez two weeks later, and a match between Valkyria and Perez for the NXT Women's Championship at NXT Stand and Deliver was made official, where she lost the title to Perez by submission, ending her reign at 165 days. On the following episode of NXT, Paxley turned on Valkyria and attacked her. On the following episode of NXT, Paxley revealed that her obsession with Valkyria was only because she had the NXT Women's Championship. Later that night, Valkyria attacked Paxley after her match, and NXT General Manager Ava announced a triple threat match for the NXT Women's Championship involving Perez, Valkyria and Paxley at Spring Breakin', where Valkyria failed to win the title in what would be her final match for NXT.
On night two of the 2024 WWE Draft, Valkyria was drafted to the Raw brand. On the May 6 episode of Raw, Valkyria made her main roster debut saving the Women's World Champion Becky Lynch from a beatdown by Damage Control's Dakota Kai, Iyo Sky and Kairi Sane, and at the same time would make her in-ring debut against Kai in the first round match of the Queen of the Ring tournament, where she emerged victorious. She proceeded to defeat Zoey Stark in the quarter-finals and Iyo Sky in the semifinals, but lost to Nia Jax in the finals at King and Queen of the Ring, marking her first loss on the main roster. On the June 10 episode of Raw, Valkyria faced Iyo Sky in a losing effort. After the match, she was attacked by the rest of Damage Control before being rescued by Katana Chance and Kayden Carter. On the June 25 episode of Raw, Valkyria qualified for the women's Money in the Bank ladder match by defeating Shayna Baszler and Kairi Sane in a triple threat match. At Money in the Bank on July 6, Valkyria lost the ladder match after Tiffany Stratton grabbed the Money in the Bank briefcase. Valkyria returned to NXT on the September 3 episode to save Tatum Paxley from a beatdown by Wendy Choo and Rosemary, reuniting with Paxley in the process. On the following day's episode of Speed, Valkyria participated in the tournament to crown the inaugural Speed Women's Championship, where she lost to Iyo Sky in the first round. Starting in December 2024, Valkyria entered a tournament for the inaugural Women's Intercontinental Championship, where she defeated Ivy Nile and Zelina Vega in the first round and Iyo Sky in the semifinals. On the January 13, 2025 episode of Raw, Valkyria defeated Dakota Kai in the finals of the tournament to become the inaugural champion.
At the Royal Rumble on February 1, she entered her first women's Royal Rumble match at number four, but was eliminated by Nile. During the following months, Valkyria successfully defended her title on Raw against Kai in a rematch, Nile, Raquel Rodriguez and Bayley. On the April 11 episode of SmackDown, Valkyria and Bayley won a gauntlet match to face Liv Morgan and Rodriguez for the WWE Women's Tag Team Championships on night two of WrestleMania 41 on April 20. Prior to night one of WrestleMania 41 on April 19, it was announced that Bayley was taken out backstage and was unable to compete. During night two on the following night, Becky Lynch, who had left WWE for nearly a year, returned as Valkyria's tag team partner, where they defeated Morgan and Rodriguez for the WWE Women's Tag Team Championships, with Valkyria becoming a double champion in the process. However, Valkyria and Lynch lost the titles back to Morgan and Rodriguez on the following night's episode of Raw, ending their reign at one day and marking their reign as the shortest in the title's history. Immediately after, Lynch turned on Valkyria. This led to a match at Backlash on May 10, where Valkyria defeated Lynch to retain the title. A rematch was then scheduled between the two at Money in the Bank under the stipulations that if Valkyria retained the Women's Intercontinental Championship, Lynch could no longer contend for the title as long as Valkyria was the champion, but if Lynch won, Valkyria had to raise her hand and acknowledge Lynch as the better woman. At the event on June 7, Valkyria lost the title to Lynch, ending her reign at 145 days. After the match, Valkyria raised Lynch's hand, but attacked her afterwards. At Evolution on July 13, Valkyria failed to regain the title from Lynch in a triple threat match also involving Bayley. The next night on Raw, Valkyria defeated Bayley in a two-out-of-three falls match to earn a rematch for the title at SummerSlam. On night two of the event on August 3, Valkyria failed to win the title in a Last Chance match, therefore being unable to challenge for the title as long as Lynch was champion.