Sophie's son, Pierre-Louis, who named his first daughter after his mother, (right), has dedicated a poem to her memory.
Sophie's blood-soaked body was discovered on a laneway leading to her isolated holiday home at Toormore outside Schull in west Cork on December 23, 1996.
Georges and Marguerite, together with Sophie's other relatives, friends and former colleagues, marked her anniversary in Paris.
The family opted not to travel to Ireland because the emotions are too painful. They will instead travel to Ireland early in the New Year.
"We despair of obtaining justice one day for her and her family," they said.
"Sixteen years after the murder of our beloved daughter, Sophie, we are always in search of justice in Ireland."
It is believed Sophie tried to flee from her assailant but was caught and killed when her clothing apparently snagged on barbed wire as she ran.
A simple stone Celtic cross inscribed with her name now marks the spot where her body was found.