The posh company which supplies lingerie to the British Monarch has lost its royal status following publication of a book revealing intimate details surrounding royal bra fittings.
Jill Kenton said her mother was already coping with the tragedy of her husband, Harold, who is suffering from dementia, and this had been further blow.
She said: "It is very sad for me that they didn't like it and I'm finding that very hard to accept".
Rigby & Peller now trades from nine stores across the United Kingdom, as well as online.
She said she was told by the Palace six months ago that they "didn't like the book" and she shouldn't have the royal warrant any more.
Describing herself as "the UK's leading boobologist" in one account to help promote the book, she noted that "even the grandest ladies need to be well-supported" and described giving the half-dressed monarch a first bra fitting.
Mrs Kenton detailed how Diana came for bra fittings, ordered Israeli-designed swimsuits and accepted posters of models in lingerie and swimwear for her sons, William and Harry, to put up in their studies at Eton. "She's wonderful. I mean, don't you think she's awesome?"
Kenton purchased the luxury brand back in 1982, telling AP she was extremely saddened by the news and unaware of the consequences the book would have.
Mrs Kenton was a regular visitor to Buckingham Palace, serving members of the Royal Family including the Queen, the Queen Mother and Princess Margaret. "I am very sad Buckingham Palace took exception to the story - it's a kind and gentle story about what went on in my life".
Yes, she really has made a boob of the whole thing, and now the company can no longer call itself the official lingerie supplier to the royal family.
Other companies that have lost their royal warrant includes Carr's Table Water biscuits, simply because they are in lower demand at the palace, and Harrods, whose owner Mohamed al Fayed allegedly angered Prince Philip with comments about the auto crash in 1997 that killed Princess Diana and Dodi al Fayed.
There would be a "gaping hole" in her autobiography if she had not mentioned her work for the Queen, said Ms Kenton, adding that she did not write the book with the intention of upsetting anyone.
"I'm coming towards the end of my life, I'm 82, so it is what it is, there is nothing I can do".
'However, the company will continue to provide an exemplary and discreet service to its clients'.
She also claimed to have given Princess Diana fittings.