 The character of Sarah March, aged 9, was created after the casting  for Charlotte, aged 10 when Shelby Sparnon, who came in to audition  looked so close to Georgie Hills appearance at that age that the  director decided to utilise the similarity. Although Georgie Hill  had blonde hair as a child, Shelby Sparnon, who was also blonde, had  to dye her hair brown to make it more believable for audiences.