Finch-Buzzard Genealogy
In "The Other Bin of Scrooge McDuck!" July 21, 2018, Webby reads from a book called The Life and Times of Scrooge McDuck that Scrooge was born in 1867.
In "Challenge of the Senior Junior Woodchucks!", April 4, 2020, Huey and Violet compete to become a senior Woodchuck, and it is revealed that the founder of the Junior Woodchucks was Isabella Finch. Scrooge and his family find the lost Journal of Isabella Finch, and a list of the lost treasures she never found. They resolve to find the lost treasures, and the foul members of F.O.W.L. decide to try to get those treasures first. And Scrooge remembers that when he was a little boy in Glasgow, Scotland, and thus in the 1870s or early 1880s, his only book was a book about the adventures of Isabella Finch.
So my rough guess was that Isabella Finch should have been born in 1857 at the latest, and possibly decades earlier.
In "The First Adventure!", November 16, 2020, it is revealed that Bradford Buzzard, Black Heron, and Mrs. Beakley were already adults during the 1960s. Since "The First Adventure!" happens in 2020 according to my chronology and in or after 2012 at the earliest, that means that all three are still very active despite having been adults for at least 43 to 60 years. Ludwig von Drake tells Bradford he hired him as a favor to Bradford's grandmother, who might still be alive in the 1960s.
In "The Final Adventure!", March 15, 2021, Scrooge calls Bradford Buzzard an octogenarian something or other, showing that Scrooge probably believes - accurately or not - that Bradford is between 80 and 89 years old, and thus would have been born between 1923 and 1940.
It is also revealed that Bradford Buzzard is the grandson of Isabella Finch and was the first Junior Woodchuck and went on many adventures with his grandmother. Ludwig von Drake confirms that Bradford was the first (and also worst) Junior Woodchuck. Bradford was probably a Junior Woodchuck somwhere between the ages of 5 and 15, and thus sometime between 1928 and 1955.
It is very rare for someone to be alive at least 155 to 163 years after their maternal grandparent is born. But that is not a record. Even in the Middle Ages, Emperor Frederick II (1194-1250) was alive 155 years after his maternal grandfather King Roger II of Sicily (1095-1154) was born.
But for a grandmother to share adventures with her grandson who lives to at least 155 years after she is born is highly unusual among humans.
For example Queen Elizabeth II (b. 1926) has a youngest grandchild, James, Viscount Severn (b. 2007), who has no doubt spent much time with her, though not on wild adventures, and will probably live to turn 80 in 2087, which would be 161 years after she was born. Elizabeth II's only maternal grandson, Peter Philips (b. 1977), is much older and would turn 80 in 2057, only 131 years after Elizabeth II was born.
Crown Prince Otto of Austria (1912-2011) no doubt often met his maternal grandmother Infanta Maria Antonia of Portugal (1862-1959), but he only lived until 149 years after she was born.
In my own family Colonel Henry Cornelius Demuth III (1897-1998) lived until 130 years after his mother Ida Elizabeth Smith Demuth (1868-1961) was born, and 160 years after her mother Martha Herr Crider Smith was born in 1838. But unfortunately I don't remember if Martha lived long enough to spend any time with her grandson - no death date is given on page 111 of this book written in 1908:
https://archive.org/details/cu31924029842204/page/n9/mode/2up.
So possibly there are stories to be told about the Finch-Buzzard family tree and how Isabella Finch lived long enough and was still active enough to go on adventures with her grandson Bradford Buzzard.