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!