Seidel has a career-high singles ranking of world No. 146 by the WTA, achieved on 6 May 2024, and a career-high doubles ranking of No. 222, achieved on 22 April 2024.[1]
Seidel was born in Hamburg, Germany and attended the Sportgymnasium Alter Teichweg school there, where she was able to graduate high school two years early at the age of 17, allowing her to focus on her tennis career.[2] She also spent time training in Kühlungsborn, a Baltic Sea resort town where her parents owned a holiday home in.[3]
Ranked No. 172, she made her Grand Slam debut at the 2024 Australian Open on her first attempt of qualifying at any Major,[5][6] where she lost to world No. 2 and eventual champion Aryna Sabalenka in the first round.