The 27 year old woman was released without charge and a file will be prepared for the Director of Public Prosecutions.
Two men, aged 30 and 32 remain in garda custody at Waterford Garda Station.
The two are detained under Section 30 Offences Against the State Act, which allows gardaí to hold suspects for up to 72 hours.
The man aged in his forties remains in a critical condition after being shot in the city on Monday.
This shooting happened outside a premises on the Carrickpherish (PRON: CARRICK-FER-ISH) Road at a quarter past 2 on Monday afternoon.
A man in his 40s was injured after being shot a number of times near the Mount Suir Apartments and was first treated at the scene by ambulance personnel.
He was then brought by ambulance to University Hospital Waterford where he's still in a critical condition.
The Irish Times reports that the victim of the shooting had been collected by a friend on Monday afternoon and they had driven to Carrickpherish Road in the city when the man asked his companion to stop the car near the Mount Suir Apartments.
It is believed the injured man went to meet two men outside a shop in the area but a row allegedly broke out between them.
It is understood one of the men pulled out a handgun and shot the injured party at least twice in the abdomen and chest.
It’s understood that the two men fled into a nearby apartment building and gardaí later used battering equipment to gain access to the building but it appeared that the men had left the building and no arrests were made.
Witnesses phoned for help and the injured man, who is understood to be from the locality.
The injured man was initially treated at the scene by paramedics before he was taken by Ambulance to University Hospital Waterford where he underwent emergency surgery for gunshot wounds on Friday afternoon.
Gardaí spoke briefly to the man at the scene and say they are keeping an open mind on the motive for the attack which has shocked people in the area which is just over 2kms from Waterford city centre.
Meanwhile it’s understood that the injured man’s companion may have accidentally hit his friend, causing lower limb injuries, as he fled the scene in his car and gardaí have since spoken to him and taken a statement.
Gardaí cordoned off the scene of the shooting for a forensic examination by garda technical experts and the road remained closed for most of Friday afternoon and evening with diversions in place.
Gardaí have also begun harvesting CCTV footage from the area to try and establish the exact sequence of events and they have appealed for any witnesses to contact them at Waterford Garda Station on 051-305300.
