Hi Terry,
If you had interrogated the Gloucestershire BMD indexes, as pointed out earlier, and requested births with father MERRETT, mother HALL, Gloucester, you would have found the following:-
Frederick George MERRETT b.1907 Gloucester 6a 301 Mar Qtr
William Joseph MERRETT b.1908 Gloucester 6a 296 Sep Qtr
Gladys Matilda MERRETT b.1910 Gloucester 6a 269 Dec Qtr
The 1911 Census will also confirm these facts.