It is unfortunate for the company who bought it from the woman who caused the problem but I would be angry if I were famous and someone wrote a book detailing a bra fitting. It was a weird and disrespectful thing to do. She got £8m from the sale of the business so, unless she had run up a lot of debts, it wasn't about the money.
I never have much respect from people in close positions, like housekeepers or nannies, who write about the people they work for. It must be unpleasant to employ people in close positions and then have them betray you. It just seems like really bad manners.