I had thought Sarah's husband John Stirling may have moved on. In 1891 census found a 47 year old John Stirling, Scotland birth, working as a shipping clerk, and with a wife who is not Sarah, at Kirkdale, Lancs - however, even though haven't tracked down the Stirlings yet, this is definitely a different John Stirling of similar age and nationality. John's maritime exploits are apparent through Australian records - in a record uploaded he is listed as a firemen and donkeyman on the James Paterson. Latest visit I can find so far is on the Quirang in 1884 at which time he was 40.
Ian