John Davies of Brymbo didn't exist? So who's this?

Jack the Ripper.John Davies, collier, of  Brymbo, died in a mining accident. Is this the husband of Mary Kelly and said not to exist? If so Mary Kelly had a child.
"c. 1879: At the age of 16 she marries a collier named Davies. He is killed in an explosion two or three years later. There is a suggestion that there might have been a child in this marriage."
According to the family records he was twenty six when he died and born in 1854. As he died in June 1880 that's a five month window to find his place and date of birth date and through him discover 'Mary Kelly'.