Kaagman joined Ajax in 2013, having spent her youth with Hollandia.[2] She made her senior on 30 August 2013 during a BeNe League draw away to Club Brugge, the first of eighteen appearances during the 2013–14 season.[1] She scored twice in eleven matches in 2014–15, prior to netting four goals in twenty-four matches in the newly reformed Eredivisie.[1] In the following two campaigns, Kaagman scored nine more goals; including her last for Ajax on 6 May 2018 against PEC Zwolle.[1] She won two Eredivisie titles with Ajax.[1]
Everton
On 22 May 2018, Kaagman joined English FA WSL club Everton in a player exchange deal involving Marthe Munsterman.[3][4] She made her debut for the club on 26 August 2018 in a 1–0 defeat against second-tier side Durham[5] in the League Cup and scored her first Everton goal in the same competition on 16 September in a 3–2 home win against Reading.[6] On 2 December 2018, Kaagman scored from 30 yards in a 2–1 win over Merseyside rivals Liverpool, the first goal scored under new manager Willie Kirk. The strike was voted as the team's goal of the season at the end of the campaign.[7][8] On 21 May 2020, Kaagman left Everton following the expiration of her contract.[9][10]
Brighton & Hove Albion
After departing Everton, Kaagman moved across the WSL to sign with Brighton & Hove Albion on 17 July 2020; penning a one-year contract.[11] She scored on her debut against Birmingham City on 6 July 2020.[12]
PSV
After 4 years in England Kaagman moved back to the Netherlands and signed for PSV.[13]