What you have posted has been extremely valuable information for me.
From what you say I have managed to trace George Foster born 1828 and his daughter Alice born 1870 back to Wortley in Yorkshire. When I saw the place name of Sheffield I did get a bit excited as the partner of the Alice I am searching for stated that he came from Sheffield, and I wondered if maybe the person that informed of her death may have thought that she also came from Sheffield (according to the 1911, Isle of Man census she came from the Isle of Wight).
Anyway, this Alice Foster did come from near Sheffield and she does appear on the 1901 and 1911 censuses so that does now eliminate the death of this particular Alice Foster from my searches.
Mary, I really must say a big thank you for your interest in this and the generosity of giving your time.
Ewan