I'm trying to discover more about the Marquise d'Assche. She was present at the Duchess of Richmond's Ball and, according to Elizabeth Longford in Wellington - The Years of the Sword, was so annoyed at Wellington's apparent nonchalance that she would "willingly have throttled him." Following Waterloo, Longford says that Lord Uxbridge joked with the Marquise, saying "I shan't be able to dance with you any more except with a wooden leg."
Longford lists Extracts from the Notebook of the Comtesse d'Assche, née d'Ives as her source for the first anecdote but I have been unable to track this work down. I assume it is unpublished. In The Duchess of Richmond's Ball David Miller mentions in a footnote that the journal Nouvelles Esquisses Brussels 1946 included an article by Carlo Bronne titled La marquise d'Assche ou les Memoires perdus but says "this cannot be traced."
If the Marquise's papers were thought lost in 1946 presumably they were found again before 1969 when Longford published her biography of Wellington. Does anyone know anything more about this? Are the Marquise's papers held in an archive somewhere?