Do you have the marriage certificate?
That would give ages, father's names, occupations etc.
Assuming you don't (otherwise you would have an idea when Gertrude was born?), FreeBMD reports that Gertrude M Butler married Arthur J Bailey in Kingsclere in September qtr 1915, Kingsclere,
Brides usually married in their home parish, so these are good possibilities from the 1901 census:
Reference RG13, Piece 1110, Folio 110, Page 7
Salters Heath, Monk Sherbourne, Basingstoke district
Butler, Frank Head M 32 Carter on Farm b Kingsclere
Butler, Ada Wife F 31 b Kingsclere
Butler, Ellen E Daughter F 9 b Kingsclere
Butler, Gertrude M Daughter F 5 b Kingsclere
Butler, Hilda A Daughter F 1 b Monk Sherbourne
Hackley, Jane Lodger Widow F 65 b Sherbourne St John
This Gertrude would have been 19 (or so) at the 1915 marriage.
Reference RG13, Piece 1119, Folio 118, Page 8
Ashford Hill, Kingsclere
Butler, Joseph Head M 55 b Kingsclere Cripple
Butler, Mary Ann Wife F 50 Monthly Nurse b Kingsclere
Butler, Gertrude Mary Daughter F 14 b Kingsclere
Butler, Harry Son M 12 b Kingsclere
This Gertrude would have been 29 at the 1915 marriage.
So, you see, buying certificates is almost essential!