There are multiple origins and translations for the name Wendy:
1. English name in a figurative sense - "friendly".
Wendy name is found in United States records from the 1800s; Wendy Gram, a female resident of Ohio, was recorded in 1828, and the name Wendy also appeared in the U. S. Census of 1880. In Britain, Wendy appeared as a boy's name in the 1881 census of England, and was occasionally used as a nickname for the Welsh Gwendolyn. However, its popularity as a girl's name is attributed to the character Wendy Darling from the play and novel Peter and Wendy by J. M. Barrie. The name was inspired by young Margaret Henley, daughter of Barrie's friend W. E. Henley. With the common childhood difficulty pronouncing Rs, Margaret reportedly used to call him "my fwiendy-wendy".
2. Various Chinese rulers have held the name and title Emperor Wen, which in Chinese is read Wen (-) di (文帝). Chinese women with the same or similar-sounding characters as their names often Anglicize their names as Wendi or Wendy.