Princess Kate has missed an expected appearance at Royal Ascot, with Prince William attending the event without her.

Kate, who shares three young children with William, has made a gradual return to public engagements this year since announcing in January that she is in remission from cancer. Kate has not shared details of the type of cancer with which she was diagnosed, though she has shared she underwent chemotherapy treatment.

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.