McCarthy was named in the Southern Vipers squad in 2020 and 2021, but did not play a match for the side in either season.[7][8] She was moved to the side's Academy squad for the 2022 season.[9] In November 2022, it was announced that McCarthy had signed a winter retainer contract at The Blaze.[10] She made her debut for the side on 7 July 2023, against Northern Diamonds in the Rachael Heyhoe Flint Trophy.[11] She played two matches overall for the side that season, taking two wickets.[12] She also played two matches for Trent Rockets in The Hundred.[13] In 2024, she played 12 matches for The Blaze, all in the Rachael Heyhoe Flint Trophy, taking 5 wickets.[14][15] McCarthy signed a new two-year contract with The Blaze in August 2024.[16]