There is a newspaper article in 1901 Sunderland Daily shipping Gazette
Fatal blow with a poker
At Newcastle police court yesterday morning, Catherine Nillson, 35 was charged with having caused the death of Dora Forster by striking her with a poker whilst in the passage of the house, 9 Theodosia Street, shortly after 7 oclock Monday night. The parties were assistants at an upholsterers and the affair seems to have arisen out of a personal quarrel and drink. Prisoner was remanded.
This is the same address as the 1901 census.
Could explain why Charles is living away from his wife in 1911. (I also see that Catherine refused to give their ages, it is scribbled on the bottom of the census)
Looking at Criminal Registers
Catherine Nilsson
Bailed 3 dec 1901
Age 35
Imprisoned
Date of Warrant 19 nov 1901
When received into custody 19 Nov surrendered in Court 18 Feb 1902
Manslaughter of Dorothy Jane Forster at Newcastle Upon Tyne 18 Nov 1901
Tried 18 Feb 1902
Verdict of the Jury No Indictment presented to Grand Jury. Not Guilty on Coroner's Inquisition
Sentence or order of the court To be discharged.