The recipe is over 60 years old and she got it sometime during their stay in New York in the late 1950s. It is a simple, moist cake with a refreshing orange flavor, and no icing–making it perfect for the summer when it can sit gracefully at the table without wilting.
After the family returned to India, the town they lived in (as most towns in India) had no bakeries. Most people did not eat eggs and cakes were not part of the cuisine. Having acquired the taste and the Western ritual of birthday cakes, she baked it at home for every family birthday. When she visited family in the US decades later, she baked the cake for her sons and grandchildren.
And in her memory it was baked for a big family birthday–hence the longing and requests for the recipe.