Threlkeld made her county debut in 2013, for
Lancashire against
Warwickshire. She scored 3
*, as well as keeping wicket. She became a regular for the side from 2014, but did not score her first half-century for the club until 2019, scoring 72 in a victory over
Nottinghamshire in the
County Championship. She also achieved her
Twenty20 high score that season, hitting 56
* against
Sussex. Threlkeld was part of the Lancashire team that won the
County Championship and
Twenty20 Cup double in 2017. She played four matches for the side in the
2021 Women's Twenty20 Cup, scoring 101 runs including one half-century, 52 against
Cumbria. She captained Lancashire in the
2022 Women's Twenty20 Cup, as well as scoring 63 runs at an average of 21.00. She played two matches for the side in the
2023 Women's Twenty20 Cup. Threlkeld was also part of
Lancashire Thunder's squad in the
Women's Cricket Super League from 2016 to 2019. She appeared in all 30 of the side's matches. She hit two half-centuries in her time there, 53
* against
Yorkshire Diamonds in 2018 (a match in which she also made four stumpings) and 52 against the same opponents in 2019. In December 2020, it was announced that Threlkeld was one of the 41 female cricketers that had signed a full-time domestic contract. She was ever-present for the side in 2021, with a top-score of 70
* in Thunder's victory over
South East Stars. She had the joint-most dismissals in the
Rachael Heyhoe Flint Trophy, with 10 dismissals. She was also ever-present for
Manchester Originals in
The Hundred, scoring 29 runs and making 7 dismissals. Ahead of the 2022 season, Threlkeld was appointed as
captain of North West Thunder, replacing
Alex Hartley. She was the side's leading run-scorer in the
2022 Rachael Heyhoe Flint Trophy, with 266 runs at an average of 53.20. She made two half-centuries in the competition, 91 against
Lightning and 79 against
Southern Vipers. She was also ever-present for Manchester Originals in
The Hundred, scoring 32 runs. She played 19 matches for the side in 2023, and was the side's leading-run scorer in the
Rachael Heyhoe Flint Trophy, including scoring her maiden
List A century, with 107
* against
Western Storm. She also played six matches for Manchester Originals in
The Hundred, making six dismissals. In 2024, she played 22 matches for North West Thunder, across the
Rachael Heyhoe Flint Trophy and the
Charlotte Edwards Cup, scoring one half-century and making 13 dismissals. Threlkeld has also appeared for various
England Academy and Development teams, and toured South Africa with the England Academy in 2018. ==International career==