Kaddish (the mourners' prayer for the departed) is recited during Scharit, Minchah, and Ma'ariv, the morning, afternoon, and evening prayers. Kaddish can only be recited if a minyan (quorum of ten men) is present. So those who come to the minyan are not just family members: it is wide open.
The husband and wife's granddaughter with have her second birthday this week of mourning. She has been in and out of the house and involved with the family as they will celebrate life even with her grandmother's passing. As the little girl's mother said to me today, We must celebrate my grandmother's life.