The use of Sunshine as a female name goes back to the 1854 novel "Tempest and Sunshine" by Mary Jane Holmes. In the novel Tempest is a nickname for the character Julia, who is called Tempest because of her stormy and volatile personality. Sunshine is a nickname for her sister Fanny, who always has a sunny and pleasant disposition. There are examples in the 19th century USA of girls named both Tempest and Sunshine because of this novel, which was a bestseller reprinted for many decades after its original publication.