In October 2022, Penickova made her
ITF Juniors debut at the J60 event in
Arequipa, where she reached the final. In February 2023, she and her sister reached the doubles semifinals of the
Petits As. Later that year, she competed in the
girls' 14&U singles tournament of the
Wimbledon Championships and was selected to represent the United States at the
ITF World Junior Championship in
Prostějov. In September 2023, she and her sister reached the
girls' doubles quarterfinals of the
US Open. The following month, unseeded at the
French Open, she reached the
girls' singles semifinals with wins over
Emily Sartz-Lunde, ,
Mia Pohánková, and
Rose Marie Nijkamp. Later that year, she and her sister participated in the Garden Cup, an exhibition at
Madison Square Garden. She also represented the United States at the
Junior Billie Jean King Cup and won the title with
Tyra Caterina Grant and
Julieta Pareja. In January 2025, she reached both the
girls' singles and
doubles finals of the
Australian Open; she was the first American to reach the girls' singles final of the tournament since 2012. In the doubles final, she and her sister won in straight sets against
Emerson Jones and
Hannah Klugman. She lost the singles final to
Wakana Sonobe. At the
French Open, she and her sister reached the
girls' doubles semifinals. At
Wimbledon, she and
Vendula Valdmannová won the
girls' doubles title, defeating compatriots
Thea Frodin and
Julieta Pareja in the final. The following month, she paired with Frodin to win the girls' doubles title at the
USTA Girls 18s National Championships in
San Diego. Later that year, she finished runner-up at the
ITF Junior Finals in
Chengdu. ==Professional career==