Rebecca made her senior debut at the London Prepares Olympic test event in January 2012. At the 2012 European Championships she made the floor final and followed up by becoming the senior all-around British Champion. She was selected to represent Team GB at the London 2012 Olympic Games and was the youngest member of the entire GB squad at just 15 years old. Rebecca placed 13th in the all-around final. In 2014 she was again crowned the British all-around champion. In the same year she was part of Team GB that won silver at the European Championships. In 2016, she claimed all-around silver at the British Championships.