During her youth career, Summanen played for both the boys and girls teams at PEPO, before joining HJK in 2016. On 10 January 2022, Summanen joined
FA WSL side
Tottenham Hotspur for an undisclosed fee, signing a contract until 2023. On 17 November 2023, she signed a new contract extension that would last until 2026. In December 2024, she won the November Goal of the Month award for her 40 yard strike against
Aston Villa. On 1 February 2026, she made her 100th league appearance for Tottenham. On 11 February 2026, it was announced that she had signed a new contract to extend her time with Tottenham, having become the Tottenham Hotspur record-holder for assists in the WSL. ==International career==