Cain began her development at the Sheffield United Centre of Excellence.[2] In 2016, Cain joined Sheffield FC in the WSL 2. In October 2016, Cain won the Future Star award at the Sheffield Olympic Legacy Celebration of Sport awards.[3] Cain left Sheffield after they were relegated to the National League for failing to meet the new Championship licensing criteria. In her final season with the club she was named Supporters' Player of the Year.[4][5]
Everton
In July 2018, Cain signed with Everton on her first full-time professional contract.[6][7] She made her debut for the Blues against Manchester City as a substitute.[8] Cain scored her first goal for the Blues against Reading in November 2018.[9] On 27 May 2020, Cain left Everton after her contract expired.[10]
Leicester City
On 4 November 2021, Cain suffered an ACL injury.[11] On 17 February 2023, she was nominated for the Goal of the Month award for her goal against Liverpool F.C..[12] On 14 July 2023, Cain signed a long-term contract with Leicester City.[13]
International career
In April 2014, Cain was named in Wales squad for an under-16 UEFA development tournament in Northern Ireland.[14] Later that year she played for Wales in an under-17 friendly against Northern Ireland.[15] Cain has since represented England on the under-17 and under-19 national teams.[16][17] In 2017, Cain was called into the under-19 squad, but would not make an appearance until 2018 to compete in the UEFA Women's U-19 Championship qualifiers scoring twice in three starts.[17]
Cain decided to switch her allegiance to Wales in September 2021.[18] She was called up to the Wales squad for 2023 World Cup qualifying matches in September 2021.[19]
Cain made her Wales national team debut against Estonia on 26 October 2021.[20]
Cain was part of the Wales squad that finished as runners-up in the 2023 Pinatar Cup.[21]