Kirk joined Posh from Women’s Super League academy side Leicester City after being at the club since the age of seven, where she made her first-team debut for The Foxes in 2019 against Reading FC. The forward also received an international call-up for the Republic of Ireland at 16 years old. Kirk certainly made a name for herself at Posh in her first season, finishing as the club’s topscorer in the FA Women’s National League with 12 goals to help the club finish fourth in the table.