Mason TJ O’Connell-Conway suffered severe head injuries at a house in Rathbane on Saturday, March 13th. He was taken to Temple Street Children's Hospital for treatment but passed away from his injuries on March 16th.
Last month gardaí arrested a man in his 30s and a woman in her 20s on suspicion of murder. They were subsequently released without charge.
Now a second woman in her 20s has been arrested as part of ongoing investigations into the incident.
A warrant was issued by a District Court Judge and the woman was arrested under Section 10 of the Criminal Justice Act, 1984.
She is now being held at Roxboro Road Garda Station under the provisions of Section 4 of the Criminal Justice Act, 1984.