Annie Zerbst is Louis' niece (Carl Jr. and Catherine Zerbst daughter). Yes Louis is Mary and Nicholas' youngest living child at the time. The best I can tell Carl Zerbst Sr., Carl Jr. and Catherine Thomas Zerbst all up and died within about 6 months of each other and of Annie being born. I just figure out where any of the three are buried. Catherine's mother is in Old Cottonwood but I can't find them there.