I am trying to find my g-g-grandmother Mary Johnson using DNA, but my g-g-grandfather had children by three different women.
My g-g-grandfather John Horlock (b1824, Horsley GLS) married Sarah Hammont and had two sons with her in Chelsea (1851 census.) He was next discovered living with my g-g-grandmother Mary Johnson in Islington (1861 census) just before the birth of my g-grandfather Tom Sansome Horlock. Mary was calling herself Mary Horlock, the wife of John, aged 23 and born in Somerset. (They didn't marry, I assume Sarah was still alive. John and Sarah's two sons were recorded on census night 1861 as staying at a homeless shelter in Saffron Hill, Clerkenwell.) They then had a daughter together, Emily Jane. Tom and Emily's birth certificates both give Mary's maiden name as Johnson, as does the birth certificate of a child who died in infancy. By the census of 1871 John was living with another woman called Mary with two additional children, Martha and Kate. They were both described as his daughters, with new-Mary calling herself John's wife, aged 38, also born in Somerset. Martha and Kate were not registered in the name Horlock; I assume they were the children of the man new-Mary was living with before, and were registered in his surname. When John and new-Mary had yet another two children, William and Mary, their birth certificates give Mary's maiden name as Poole. Martha died in childhood and Kate took up with one Henry Sessions, who spent so much of his life in prison that they did not have children.
I have taken a DNA test with Ancestry and have a sprawling tree there. Of all my matches, I can find only one who is a certain, documented descendant of Emily Jane. I'll call him Alf. When I look at the DNA matches which Alf and I have in common, those I am able to build a tree for all turn out to be descendants of Mary Poole through William and Mary, her children with John. (There are a couple of our shared matches who have no tree or clues, so I can't trace their ancestors.)
I can find plenty of matches who trace back to Tom Sansome but they too, of course, have John's DNA as well. I need to find a match who is decended from a relative of Mary Johnson, or from a child she had with another man, in order to eliminate John's DNA and find out who Mary was. (Is my logic correct here? Looking at DNA matches gets me back, at best, to people who are descended from John and any one of three or more women.)
I have built trees for all the Mary Johnsons born around 1838 in Somerset from entries I can find on the 1841 and 1851 censuses. They all died too soon, married elsewhere or emigrated. I have messaged all the no-tree people but got no joy there. I have access to the DNA matches of my sister, my cousin and a niece on Ancestry (all descended though Tom Sansome.) I have transferred my DNA results to MyHeritage, familytreeDNA and GEDmatch but am unsure how to use their tools and they can't rival Ancestry for the huge number of trees and DNA test takers. I've tried to find out who Mary Poole was on the off-chance that she and Mary Johnson knew each other back in Somerset - she, too, has eluded me.
I have been looking for Mary Johnson since the arrival of the internet. I thought that DNA would crack the case, but now I'm struggling with the DNA side of things. Can anyone suggest a way forward, please? On Ancestry.co.uk I am ali_aitch1 and the tree is called Seeking Mary Johnson. Thanks so much for reading. Alison x
