A 23-year-old woman has been arrested in connection with the shooting in Parslickstown, Mulhuddart, Dublin, the Irish Mirror reports.
The incident left a baby boy, his mother, and his 17-year-old uncle injured.
The young woman was detained in the Wicklow area and is being held under the provisions of section 30 of the Offences Against the State Act 1939 as amended at a Dublin Garda Station.
Gardaí have also found a gun.
They said in a statement, "Gardaí can also confirm that they have recovered a firearm as a result of searches in the Parslickstown area earlier today. The male arrested yesterday in connection with the incident remains in custody."
17-year-old Matthew 'Matsie' Collins and his infant nephew John Collins underwent surgery last night after the close-range attack. The baby boy was taken to Temple Street Children's Hospital and the teenager was rushed to Connolly Hospital in Blanchardstown.
The baby's mum, 29-year-old Lynn Doyle, was holding her child when a person started shooting them with shotgun pellets. Matsie was shot in the stomach.
Thankfully, their injuries are not believed to be life-threatening.
It is thought that the attack was the result of a feud within the Traveller community, the Irish Times reports.
Arthur Collins, father of Matsie and grandfather to John, told the Irish Times that the incident was 'all over a dispute that happened two or three years ago, but we thought it was all over'.
Superintendent Liam Carolan from the Blanchardstown Garda Station said that 'there is a quite volatile situation' surrounding the shooting. He also commented that it was too early for any speculation on 'who or what has been involved'.
He urged anyone with information to come forward, saying, "Anyone who was in the vicinity of Parlickstown Gardens from 12 noon — if they saw a car driving at high speed, if they saw people hanging around or thought something seemed strange, anything like that.
“We’ve set up an incident room at Blanchardstown Garda station if they could contact us there on 016667000 or the confidential line 1800666111."
We hope that the victims make a speedy recovery.