A member of TK Sparta Prague, Samsonová won her first junior title as a 13 year-old at a J5 event in Prostějov in a October 2021, without dropping a set. It was her first junior-level event. She then won her second J5 event in November 2021 in Silla-Saledar in Spain, and reached the final in her third, in Montemar.[2][3]
In July 2023, she won the final of the Girls' doubles alongside compatriot Alena Kovačková. In the final they faced Hannah Klugman and Isabelle Lacy of Great Britain, winning in straight sets. It was the first Czech pairing to win the title since Barbora Krejčíková and Kateřina Siniaková in 2013.[4]