The thread on Frederick George Coates a few days ago gives references to suggest that Gertrude Emily Sterry was actually William Coates housekeeper not his daughter. This seems to be borne out by the censuses of 1871 and 1881 which list that William and his wife Eliza had five children, Annie b1869, Emily b1871, William b1874, Jane b1877 and John b1879. By the 1891 census William and his wife had parted, he stayed in Cheltenham and she went to live in Gloucester.
Gertrude Emily Sterry is listed on the BMD index and the 1881 and 1891 censuses as coming from Longhope. There are no birth, marriage or death records to indicate that she was William Coates daughter or that she had been married and widowed by the age of 23 in 1901.
William's wife was actually still alive in 1901 so the census listing as a widower was inaccurate.
Gertrude's sons Frances (b 1898) and Frederick George (b 1900) are both listed on the GlosBMD birth index as COATES, mother's name Sterry, both born in Cheltenham which would indicate that they were William's sons, not his grandsons