I would guess that the girls were born around the turn of the century in the United States.
DD: Lucida Margaret
DD: Eldora Jean (or Eldora Charlotte)
DD: Regina Florence
or
DD: Lucida Frances
DD: Eldora Mabel - Eldora Mae and Eldora Charlotte would also work.
DD: Regina Pearl
I also like Lucida Claire, Eldora Jean, and Regina Mae.