The ambulance service was called to a house in Great Yarmouth, Norfolk, at about 11.40pm on 5 August following reports that a woman had fallen down the stairs.
The woman, Linda Rainey, 60, died two days later at Addenbrooke's Hospital in Cambridge after being admitted with serious head injuries.
On Tuesday, 55-year-old Rosalind Gray, of Malborough Square in Great Yarmouth, was charged with murder.
She has also been charged with conspiring to pervert the course of justice.
A second person, Adrian Lawrence, 53, of South Market Road in Great Yarmouth, has also been charged with conspiring to pervert the course of justice.
Both suspects are due to appear in Norwich Magistrates' Court today.
Officers say they received "significant information" about the incident from a member of the public on 10 August.
A post-mortem found that Ms Rainey died of a serious head injury.
Ms Rainey's family said in a tribute issued through police: "Linda (Lin) was the much loved mother of five children and grandmother to four grandchildren whom she adored.
"She was also a popular member of the community.
"Her death has come as a huge shock for us."