The little girl, believed to be from Limerick, was in Ballybunion, Co Kerry, with her parents for the weekend.
She and the other children were crossing the road shortly before midday yesterday when she was struck by the car. She died a short time later.
A postmortem examination was due to be carried out on her body at Kerry General Hospital last night.
Listowel gardaí have appealed for any witnesses to the accident to contact them on 068-50820.
The girl’s death brought to 134 the number of people killed in road accidents since the start of the year.
Elsewhere, a postmortem examination was due to take place today on a young man struck by a car in the Donegal International Rally outside Letterkenny.
Richard O’Donnell from Strabane, Co Tyrone, had been standing among a group of about 150 spectators at Ballyarr, watching the race. The 18-year-old tried to cross the narrow country road during the race and was struck by one of the cars. He died instantly.
One bystander, a young man who didn’t want to be named, said: “It was dreadful.
He was thrown up in the air by one of the competing cars, a Ford Fiesta. The driver had no chance of avoiding him.”
Gardaí and rally organisers said no blame was being attached to the driver who, along with the co-driver, was treated at the scene by an ambulance crew. The remainder of the three-day rally, organised by the Donegal Motor Club, was cancelled.
It was the second time in six years that the rally has been abandoned in tragic circumstances. It was called off in 2002 following the deaths of two marshals and injuries to a photographer in an accident on the opening day.
Meanwhile, student Aoife McEvoy died instantly on Saturday when she was struck by a car after getting off a bus at a stop in Rathcormac near Sligo town.
Aoife, aged 20, was the youngest in a family of three.
Anyone with information about the accident is asked to contact gardaí at Rosses Point on 071-9177143.
Ann Kerrigan, 17, from Towneymoyle in Manorhamilton, died in Sligo General Hospital on Saturday evening, 12 hours after sustaining serious injuries when the car in which she was a front-seat passenger overturned at Brackery Beg on the road to Rossinver.
Two men in their early 20s, the driver and another passenger, were treated in hospital for minor injuries.
An elderly man was in a critical condition in hospital last night following a crash in Co Galway. The man and his wife were travelling near their home when their car collided with a pick-up truck on the Loughrea to Woodford road shortly after 9am on Saturday.