The heartbroken family of the dead woman described how they faced burying a second sister, following the death of another sibling some years ago.
The body of the 31-year-old, named locally as Breda Cummins, was found by gardaí in the upstairs room of a house in the Michael Dooley Terrace estate in Athy.
A man at the scene of the attack was left with wounds on his hands.
He was taken to Naas General Hospital, where his condition was said to be not life threatening last night.
Gardaí were called to the scene of the stabbing just after midnight when the alert was raised.
The woman had received one stab wound in her chest and was later pronounced dead at the scene.
Gardaí arrested a 48-year-old man and he was taken into custody for questioning at Kildare Garda Station.
It is understood the attacker was known to the woman.
Ms Cummins was originally from Celbridge and had only been living at the Michael Dooley Terrace house for a number of weeks before the fatal stabbing. She was the mother of a 13-year-old boy, according to local reports.
The victim’s sister, Sabrina, described how the family were heartbroken over the death.
Breda “wouldn’t hurt a fly” and “didn’t deserve this”, she told RTÉ.
Members of the Cummins family gathered outside the scene and were seen speaking to investigating gardaí.
Another sister, Joanna, told reporters how her mother had been speaking to Breda only hours before she was attacked and that she was laughing, singing songs and was in great form.
The family had already lost one sister a number of years earlier, one of the sisters revealed, adding: “It’s not fair. We already buried one sister and we’re burying a second sister.
“And my mother is heartbroken, she’s not able for this. The pain is killing all the family. I just can’t believe what some people are like and why this happened to our sister.”
Gardaí technical experts were at the sealed-off house while a postmortem was scheduled to take place at Naas General Hospital.