In June 1815 Waldie was on a family visit to Brussels, coinciding with the Waterloo campaign. She and her sister, Jane Waldie, wrote an account of her experiences, published in 1817 under the title of "Narrative of a Residence in Belgium, during the Campaign of 1815, and of a Visit to the Field of Waterloo." A second edition was published in 1853 as "The Days of Battle, or Quatre Bras and Waterloo; by an Englishwoman resident in Brussels in June 1815". The edition of 1888 was entitled "Waterloo Days". The book was heavily quoted by Augustus Hare.