Complex sentence: Between the ages of 11 and 15 she trained at the Francis Cooper School of Dance whilst attending Cator Park School for Girls but at 14 she left Cator Park to pursue acting more seriously at the BRIT School for Performing Arts in Croydon.
Split into simpler sentences: Between the ages of 11 and 15, she trained at the Francis Cooper School of Dance whilst attending Cator Park School for Girls. Hwwever, at 14 she left Cator Park to pursue acting more seriously at the BRIT School for Performing Arts in Croydon.