According to deaths Dorothy Elsender was born 26/07/1924 and died 2012 Newcastle, I wonder if this is the right one
Using the free search to the 1939 shows Dorothy Calvert/Elsender was indeed born in July 1924.
The Dorothy who was born Newcastle, mother's maiden name Braithwaite was born 1925 (or at least that's when her birth was registered).
Again using the free search to the 1939 reveals that in the same household with Dorothy was a sister born 1929, called Edith.
Looking at her birth, Edith's mother's maiden name was
Kerr