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JohanEdla
JohannaPetrusNilsAlma EmiliaEmma EleonoraSigfridSigne LinneaOskar
My great-grandmother had almost as many siblings as your great-grandfather, that is 12. I've posted their names here once before, but here they are again:
Samuli Vihtori
EmilHemmi (male)
Lyydia ElinaHilda Effia
Verner EdvardJulius Valfrid
Tyyne VilhelmiinaHelmi HiljaAino Attilia
Olga Helena (my great-grandmother)
Laina
Uuno
Valdemar