The body of Kate Barry, singer/actress Birkin's daughter with composer John Barry, was found outside her apartment block in the French capital last week (11Dec13).
It is believed the photographer took her own life by jumping from her fourth floor balcony.
A memorial service was held at Paris' Eglise Saint Roch church, with her famous mother and actress half-sister Charlotte Gainsbourg leading the mourners.
Deneuve, a longtime family friend, was in attendance and carried a reef of white flowers into the church, while former French President Nicolas Sarkozy's singer wife Carla hid her tears behind sunglasses.
The congregation then moved to the Montparnasse Cemetery, where the body was laid to rest.
Barry's father, who was the longtime Bond music composer, died in 2011.