Question

Hello Rabbi,
My father passed away a year ago. In another week, the one-year memorial will take place. We are a relatively small family: two sons and a daughter. There is also our mother (the widow), and grandchildren, thank God.
Our question: is it permissible for us to say Kaddish in a gathering of 10 family members who are of bar/bat mitzvah age? That is, with 5 men over bar mitzvah age + 5 women over bat mitzvah age?
Otherwise, it requires us to bring in a “completion” for the minyan, probably kollel students from a nearby kollel who would come to answer Kaddish. It undermines the intimacy of the memorial, and in general, they have no connection to it.