After graduating high school in 2010, she decided to forego the popular U.S. college route and train at home to become a professional golfer in Europe.

She chased a maiden LET title at the 2021 Dubai Moonlight Classic, where she shared the lead with LPGA Tour player María Fassi ahead of the final round.

In June 2022, Karlsson fired a career-best round of 63 to hold a three stroke lead at nine-under-par after the first day of the Amundi German Masters.

[10][11] She led until the 72nd and final hole where a bogey meant she finished in second place, one stroke behind compatriot Maja Stark who fired a sensational approach which was a whisker away from dropping in for eagle.

[15] In March 2023, Karlsson announced she had sustained a knee injury (meniscus) and was scheduled to undergo surgery, potentially missing much of the season.