PhilTurner on Family Tree Circles

My grandfather William Thomas Turner was born in Norwich, Norfolk, U.K on the 14 July 1891 in 18 Chapel Street, Union Place, Heigham, Norwich, Norfolk, U.K.
His mother was Harriette Parker born in Cir 1873 Norwich, Norfolk, U.K
Though William Turner was not on the Birth certificate, he was the father of William Thomas Turner.
William Turner was born in the village of Beighton, Norwich on the 12.06.1869, to the parents of Samuel & Hannah Turner ( Nee Skipper ).

Samuel recorded William Turner's Registration on the 7.7.1869, in the Birth Register in the District of Blofield, column No.268 in the book No.11 of birth's, in the Sub-District of South Walsham, Norwich.
At this time Samuel recorded his occupation as a farm labourer.

Sometime between the years of 1869 - 1881, the family moved from Beighton to the village of Acle, Norwich, this was borne out by the 1881 census.

In the Beighton census of 1871. Samuel was the head of the house and aged 40 years and still an Agrigultrial Labourer.
With Samuel Turner at this census was his wife Hannah Turner, aged 31 years old. and their children:-
Eliza Turner, daughter aged 12 years. ( where were you in the 1861 census ).
Mary Ann Turner, daughter aged 9 years.
Harriet Turner, daughter aged 7 years.
An Unknown daughter aged 5 years.
William Turner, aged 1 year old.
Samuel's Mother-in-law, Harriet Skipper, Widow aged 61 years.
If Harriet Skipper was a widow in 1871 she may have married sometime between the census of 1861 & 1871, as she was unmarried in the census of 1861.
Also, if Harriet Skipper did marry who was the person she married and why was she using her maiden name in the 1871 census?.