[3] She is best known for her role as Sister Michael in the teen sitcom Derry Girls which earned her a BAFTA Award.
From 2018 to 2022, McSweeney played the role of Sister Michael in the Channel 4 sitcom Derry Girls written by Lisa McGee.
Outside acting, McSweeney has also made guest appearances on television shows including Sunday Brunch and Front Row Late.
In 2023, she appeared in a celebrity episode of Catchphrase winning almost £30,000 for her charity, The Maya Centre in North London.
On 8 November 2019, McSweeney's flat in London caught fire due to a cube double adaptor that had fallen out of the socket.