Mrs Delia Conroy of Churchtown, Co Cork, lost her 21-year-old daughter, Carmel, and 21-month-old granddaughter, Emma, in a crash two years ago this week.
Carmel's best friend, Niamh O'Herlihy (19), and Niamh's sister, Anita (17), also died.
The car in which the four were travelling was in a collision with another vehicle on the main Cork-Limerick road, less than a mile from Charleville.
The Conroy and O'Herlihy families have placed two headstones and a large photograph of the victims at the location of the accident. A man had been killed in a two-car collision close to the same spot just eight months previously, Mrs Conroy said.
"It isn't a bad bend, so to know what to do about it is so hard. Our area seems to be quite bad for it, but I really don't know why. All I know is that we have lost so much now.
"I think the only thing would be to put up cameras near there. I would suggest there would be either cameras in that spot or that police would be there, but of course you can't have them everywhere."
Carmel Conroy and her friends had formed a band called Nivita. They had released a tribute record for the victims of the Dunblane massacre of school children in Scotland and were out putting up posters for a concert on the evening the accident occurred.
"Our house used to be full of music, song and laughter," said Mrs Conroy. "The wound is as sore today as it was the day it happened. In fact, it's worse because you're in shock for such a long time. The reality is we will never have them back again.
"We'll never get over it, never in our lifetime. We are just different people. Our lives are shattered."
Mrs Conroy and her husband, Colm, were surrounded by family this week during the second anniversary of the deaths of Carmel and Emma.
The couple have two other daughters, Joan and Theresa, who each have four children, and three sons, Billy, Kevin and Colm.
"Carmel was our baby. Between my eldest daughter and her there was 20 years so she was a big surprise. Then we were rearing the little one; she was our life. I buried them together in one coffin," said Mrs Conroy. "It hasn't just destroyed our lives, it's destroyed so many lives. The O'Herlihys have lost two daughters."
Niamh O'Herlihy had been studying journalism in Dublin but had broken off her studies to pursue a career in music. Her sister, Anita, was working with a model agency in Cork.