It was due to be offered in the Charterhouse auction in Sherborne, Dorset, on March 2-3, with an estimate of £10,000-15,000.
However, the family that owned the sketches came to an arrangement with the trust at St James’ Palace, London, before the sale.
Found when clearing a family property, it dates from 1885. On the book cover is her monogram under a crown and on the inside it is inscribed On board the steamer Le Petit Parisien on the Lac de Bourget Ap[ril] 11 1885 and on its pages are numerous pencil and watercolour drawings of dogs, train and continental journeys, mountains and lakes, and a view at Frogmore, Windsor, dated July 1886.
A family member of the sketch book owners, Leta Smith, worked as a royal archivist in Windsor Castle from 1924-57.
She was awarded various medals for her service, including an MVO (Member of the Victorian Order) presented to her by Queen Elizabeth II, which were also set to be included in the auction.