| Ann Angeline Hanvelt née Plaza was | 20 years | old when she bore a son (Fredric Duane Hanvelt "Dewey") |
| Henrietta Plaza née Zulowski was | 21 years | old when she bore a daughter (Frances Uhren née Plaza) |
| John Plaza was | 23 years | old when a daughter was born to him (Mary Plaza) |
| Henrietta Plaza née Zulowski was | 23 years | old when she bore a son (John Plaza) |
| John Plaza was | 25 years | old when a son was born to him (Mike Plaza) |
| Henrietta Plaza née Zulowski was | 25 years | old when she bore a son (Anthony Walter Plaza "Tony") |
| Anna Plaza née Wojtowicz was | 26 years | old when she bore a daughter (Mary Plaza) |
| Henrietta Plaza née Zulowski was | 27 years | old when she bore a son (Peter Plaza) |
| Anna Plaza née Wojtowicz was | 28 years | old when she bore a son (Mike Plaza) |
| Henrietta Plaza née Zulowski was | 29 years | old when she bore a daughter (Ann Angeline Hanvelt née Plaza) |
| Michael Plaza was | 31 years | old when a daughter was born to him (Frances Uhren née Plaza) |
| Henrietta Plaza née Zulowski was | 32 years | old when she bore a son (Frank Joseph Plaza) |
| Michael Plaza was | 32 years | old when a son was born to him (John Plaza) |
| Michael Plaza was | 34 years | old when a son was born to him (Anthony Walter Plaza "Tony") |
| Henrietta Plaza née Zulowski was | 34 years | old when she bore a daughter (Mary Sobieski née Plaza) |
| Michael Plaza was | 36 years | old when a son was born to him (Peter Plaza) |
| Michael Plaza was | 38 years | old when a daughter was born to him (Ann Angeline Hanvelt née Plaza) |
| Michael Plaza was | 41 years | old when a son was born to him (Frank Joseph Plaza) |
| Michael Plaza was | 44 years | old when a daughter was born to him (Mary Sobieski née Plaza) |
| Henrietta Plaza née Zulowski was | 46 years | old when she bore a daughter (Angeline Kurpiel née Plaza "Angie") |
| Michael Plaza was | 56 years | old when a daughter was born to him (Angeline Kurpiel née Plaza "Angie") |
| There were found 21 births for which we know the parent's age at the event (parent's and child's year of birth). Average age of having children is 36 years for males and 28 years for females. |