In the ghetto apartment, a family’s dear, lifelong, elderly friend, called Grandma but not biologically related to them, dies. They plan to have a funeral and bury her in the Jewish cemetery near the ghetto (this was at a time when it was still allowed). There are 6 people left in the family living with her, including 2 children and the mother, so no minyan. When she dies, would the family informally, emotionally, say Kaddish, at least once, or would this not be done?
Kaddish should not be recited unless there is a minyan present. If there is a minyan, a non family member may say kaddish. If there is no kaddish at the burial, a minyan should be gathered at another place to say kaddish. There are other prayers which could and should be said without the minyan. After saying all this, the holocaust gave rise to unusual, often unthinkable and inhuman situations. The reactions of people, spiritual and emotional, may have found favor in the eyes of G-d even if not justified on a pure halachic level.