By Joseph Wilkes & Rebecca Russell Prince William and Kate Middleton are reportedly hatching surprise plans to transform a secret home into something of a sanctuary as part of the Princess’s recovery process. The Royal couple is said to be contemplating renovations and extensions to a little-known redbrick annexe adjacent to their Adelaide Cottage residence in Windsor. The family, who relocated to the Berkshire estate towards the end of summer 2022, currently divide their time between the four-bedroom cottage and their cherished Anmer Hall retreat on the Sandringham Estate. While Adelaide Cott…