Hi Mike,
I had heard of the possible Ismay/Rosenbaum story before from another source. When I was researching the Empress of Ireland's passengers for Dave Zeni's book I came upon the Cheape family (landed gentry with property in the South and Scotland). The Cheape's lost a married daughter, Catherine Beatrice Cay, in the Empress disaster and one of Bruce's sisters had married into the Cheape family. Of course, this was in the days of the great house parties when virtually an entire family would descend on one of the ancestral homes for the weekend. I was told by the family that during the period around 1910 Bruce Ismay had been to one of these gatherings with an American lady "known to be not his wife" and that the Cheape family had wondered how the two had ever been thrown together as Ismay himself was reserved and extremely shy to the point of rudeness. His companion, whose name my informant could not recall (she would of course have been a very small child - but small children love to listen in!) was just the opposite, brash to the point of being vulgar and deemed "thoroughly unsuitable for an English Gentleman's Mistress!!" by the family. Whoever she was, and I really couldn't say if it was Edith, was no looker - in fact one of the family referred to her as looking like "a bulldog chewing a wasp!"
I had rather formed the opinion that if Ismay did indeed have a paramour aboard the Titanic, then she would probably be unlisted which is why I raised the point about the telegram.
Hope all is well with you Mike - I had a two hour phone call from Bob the other night in which we put the world to rights!
Geoff