Hi
I think it's because he is listed twice, once as Samuel Edwards-Williams and once as Samuel Edward Williams. She is Phoebe Louisa.
That one was Sept quarter 1888. This could fit as the couple are married on the 1891 census. By the 1901 census they have two children, the eldest Horace aged 9. As Nanny Jan says, the safest way is to send for Horace's birth certificate.
This could be his birth:
Horace Edwards
March quarter 1892
Kidderminster
6C 234
Jan