Rooskrantz trains at the Johannesburg Gymnastics Centre, and started gymnastics at the age of eight. She made her international debut at the 2015 Top Gym Tournament in Belgium, placing ninth in the all-around and sixth on the uneven bars and balance beam. She came second in the junior all-around event at the
African Championships. She nearly swept the gold medals at the 2016 South African Championships but finished second on the balance beam to
Naveen Daries. At the 2016 Junior Commonwealth Games in Namibia, she won silver medals in the all-around, uneven bars, and team events and a bronze medal on the balance beam.
Senior 2017–2018 Rooskrantz became
age-eligible for senior competitions in 2017. She made her senior debut at the 2017 Koper Challenge Cup, finishing fifth on the uneven bars. At the Africa Safari International, she won the bronze medal on the uneven bars. She then won the all-around title at the South African Championships. As a result of her national championship win, she qualified for the
2018 World Artistic Gymnastics Championships in
Doha, Qatar.
2019–2021 Rooskrantz began the 2019 season by winning the uneven bars title at the South African Championships. She then won the uneven bars gold medal
Szombathely World Challenge Cup. At the
2019 World Championship, she finished 68th in the all-around and
qualified for the 2020 Summer Olympics. She was the fourth South African artistic gymnast to qualify for the Olympics since South African re-introduction in 1992 and the first since
Zandre Labuschagne in
2004. Rooskrantz finished seventh on the uneven bars during the qualification round of the
2020 Baku World Cup. However, the event finals were canceled due to the
COVID-19 pandemic. As the 2020 Summer Olympics were delayed due to the COVID-19 pandemic, Rooskrantz
livestreamed the routine that she would have performed at the Games in August 2020. She finished 61st in the
qualifying stage of 2020 Olympic Games and did not qualify for any finals. Her score at the Games was a
personal best. She also won the uneven bars event at the
African Championships. She also won the African all-around title and qualified for the upcoming World Championships. Then at the
2022 Commonwealth Games, she won the bronze medal on the
uneven bars. She was the second South African female gymnast to win a medal at the Commonwealth Games. She finished ninth in the
all-around final, and she was part of the South African
team that finished fourth. She finished 47th in the all-around during the qualification round of the
World Championships.
2023 Rooskrantz won the all-around and uneven bars titles at the South African Championships. She then helped South Africa win the
African Championships team title for the first time since 2006 and qualify for the World Championships, and she finished second in the all-around to
Kaylia Nemour. At the
Paris World Challenge Cup, she finished fourth in the uneven bars final. Then at the
World Championships, she finished 46th in the all-around during the qualification round, securing
qualification for her second Olympic Games.
2024 Rooskrantz began the season at the South African Championships and finished second in the all-around. In the event finals, she won gold on the uneven bars and balance beam and silver on the floor exercise. She then finished eighth on the uneven bars at the
Antalya World Challenge Cup. At the 2024 Olympics, she placed 25th on uneven bars, and 73rd on both balance beam and floor exercise.She however had to withdraw without finishing due to an ankle injury she suffered during her floor exercise routine. ==Personal life==