I wonder what else it features. Presumably it's set in today's world, judging by the trite and tired names of the twins.
Jut for fun, I looked up the actual turn-of-the-20th century children, in age order:
Anne,
Ernestine (
Ern),
Martha (
Mart),
Frank Jr.,
Bill,
Lillian (Lill),
Fred,
Dan,
John (
Jack),
Bob, and
Jane
I dislike
Ern for a boy, and for a girl it's dreadful; I also find
Bill, closely followed by Lill(ian), unfortunate. There was also a girl named
Mary who died young.