Catherine, Princess of Wales dropped out of a planned engagement at Royal Ascot at short notice on Wednesday. Kate, 43, had been expected to join her husband Prince William as well as King Charles and Queen Camilla at the horse racing event. Racegoers were hoping to see the popular royal during the traditional carriage procession at the racecourse.

Catherine has slowly returned to public events after cancer treatment and had been expected in the procession of Royal Ascot, but she abruptly canceled.

The princess canceled plans to attend the horse racing event on Wednesday as she tries to find the “right balance” in her recovery from cancer, Kensington Palace said.