[5][14][15] In 2008, when still a schoolgirl at Muckross Park College, O'Flanagan was a member of the Hermes team that won the All-Ireland Ladies' Club Championships.

In 2012, along with Dora Gorman, Chloe Watkins and Deirdre Duke, she was a member of the UCD team that defeated Loreto 3–2.

[23] In 2013–14, together with Katie Mullan, Gillian Pinder, Deirdre Duke, Nicola Evans and Emily Beatty, O'Flanagan was also a member of the UCD team that won the Women's Irish Hockey League.

[27][28] In 2015–16, together with Chloe Watkins and Nicola Evans, O'Flanagan was a member of the Hermes team that won the Women's Irish Hockey League title and the EY Champions Trophy.

[39] In March 2015 O'Flanagan was a member of the Ireland team that won a 2014–15 Women's FIH Hockey World League Round 2 tournament hosted in Dublin, defeating Canada in the final after a penalty shoot-out.

[38] In January 2017 she was also a member of the Ireland team that won a 2016–17 Women's FIH Hockey World League Round 2 tournament in Kuala Lumpur, defeating Malaysia 3–0 in the final.

[2] O'Flanagan represented Ireland at the 2018 Women's Hockey World Cup and was a prominent member of the team that won the silver medal.

[56][57] Source:[2] Together with Lizzie Colvin, Nicola Evans, Deirdre Duke and Gillian Pinder, O'Flanagan was one of five lawyers in the Ireland squad at the 2018 Women's Hockey World Cup.