My G G Aunt Elizabeth Porter (1835 - 1907) was initially married to William Wilson with whom she had 4 children before he died in 1868. I have all their details and have checked the GRO so I'm fairly sure their were only 4. In 1871 she is living in Heckington as Elizabeth Wilson laundress, with 3 of her children and a visitor, Joseph Thacker. Between 1871 and 1881 Elizabeth has 4 more children, Mary Ann Thacker Wilson b. 1871 in Heckington, William Wilson b. 1873 Gillford Hill, Yorks, Margaret Wilson b.1877 Wortley Yorks and Sarah Thacker b.1879 Market Deeping and they all have the mothers name as Porter in the GRO index. Obviously with William Wilson long gone it's fair to assume Joseph Thacker was the father and they all have Thacker as their surname in the 1881 census. I have their baptism details, but have so far not researched them in later life.
So far so good, but in the 1881 census Elizabeth is recorded as head of the family, so where is Joseph? I've looked, but I can't find him for certain in any census after 1871, neither can I find a death registered, so what happened to him? I also can't find a marriage between Joseph and Elizabeth, so I'm sure they did not get married. Finally if he was the father why are the first 3 children born post William Wilson's death given Wilson as their surname?