Her body was discovered at a house in Dill Avenue in Lurgan on Tuesday evening.
A post-mortem examination has now been carried out to establish the cause of death.
A man arrested and taken into custody has now been released, say police.
In a statement, the PSNI said this evening: “A man arrested by police in Lurgan examining the circumstances surrounding the sudden death of a woman whose body was found at a house in Dill Avenue in the town yesterday evening, Tuesday 3 April, has been released unconditionally.
“A post mortem examination has been carried out.
“This death is not being treated as suspicious.”
DUP Upper Bann MLA Carla Lockhart said: “My first thoughts are with the family of the deceased lady.
“This is a very sad time for them and I would ask they are given some privacy to grieve their loss.
“The death of a family member at any time is sad but particularly so when it is sudden and the cause of death uncertain.
“I have been liaising with the PSNI and am aware that someone remains in custody following an arrest yesterday.”