'Once I Had A Home', The Diary and Narrative of Nadejda, Lady of Honour to Their Imperial Majesties The Late Empress Alexandra Feodorovna And The Empress Maria Feodorovna of Russia, published October 1926 by Duckworth (London), with a 2nd impression March 1927. 320 pages, no illustrations.
Yes, her real name was Marchioness Felise Maureen de Verdieres, only child of an Imperial Guard officer. Most of the names of people in her memoirs are also changed 'to secure the safety of those still in the danger zone, to respect the privacy of certain relatives...and to preserve the incognito of some of the living characters'. This of course limits its value as an historical document, but it is still a useful account of how the two revolutions of 1917 affected members of the aristocracy and effectively destroyed their way of life. The author is by turns angry, romantic, gossipy and bitter in her descriptions, but she is always sincere and her love of Russia is clear at all times. Her final description of the 'lonely, black-robed figure, dignified and sorrowful' of the Dowager Empress on board 'Marlborough' is quite powerful.
The book is quite hard to find now, but worth the trouble.
Felise (though her birth name was Phyllis) de Verdieres was actually the daughter of a British artist named Gotch. It is the pseudonymous author "Nadejda" I guess who claims to be daughter of a Guards officer. Your post showed up as part of an investigation by a name authority cataloguer who referred this query to me - at least the second time that one of my colleagues has chanced across this forum in answering reference or other queries. :-)
Greg King and I have both examined this book over the last couple of days; I would go so far as to say that it is fiction, because there's no doubt that Phyllis Maureen Gotch wrote it - her entry in Women's Who Who for some date in the 30s lays claim to it, hence it was attributed this way in a note on the British Museum catalogue as well, despite the title page.
I don't know if you have any contrary info indicating that the book is genuinely a memoir which Gotch ghosted or something similar (?), but thought you would be interested to hear about the way that your old post showed up.....Certainly, the plethora of remembered conversation in the book would lead one to consider it fiction, or, at best, heavily fictionalized. It has a strongly anti-Bolshevik agenda.