Hello Annette
The 1911 Census for Edward Hunter where his wife Sarah is age 39, I have printed off.
Going by Sarah's age, she was born 1872.
The family on this 1911 is correct.
Edith and Florence is on the 1901 Census with their grandparents, the Cross family, this also is
correct.
I have found a Sarah Smith on the 1891 where she is 19 yrs old and a domestic servant,Single, born Birmingham. On this census she is in Handsworth, not far from where she lived.
I looked for a birth for Sarah in 1872 and found 2, parents for the one was John Henry and Elizabeth, and parents for the other one was James and Sarah, which could be the one as the name Sarah is carried through.
The marriage of Sarah Florence is the WRONG one in 1892, and like you, I cannot find a marriage for 'my Sarah' who according to the 1911 had been married for 11 years, taking that from 1911 gives us the marriage date of 1892

On the 1901 Census, I have found a Sarah Smith born 1877 with parents James and Sarah.
Sarah age 24 is a French Polisher and single, born in Birmingham.
This is going from bad to worse:(
I really don't know what to do:( Whiskey and Paracetamol???
Regards
Gillianr