Tinker Bell's transformation from a spot of light dancing about a stage to the winged pin-up girl we see everywhere today is directly a result of the 1953 Disney animated film.
Tinker Bell had appeared on film before, in a 1924 version of Peter Pan.
However, when Disney artists began work on their own version, they had their own preferences for the character. Two of the principal animators at the studio wrote that story artist 'Joe Rinaldi wanted Tinker Bell to look more like the popular bathing beauties of the time," according to Murray Pomerance in Tinker Bell: The Fairy of Electricity" in Second Star to the Right: Peter Pan in the Popular Imagination. The human model for Tink was Margaret Kerry, an actress known as "The Best Legs in Hollywood" (not Marilyn Monroe, as has often been rumored). Kerry also provided the voice of the red-haired mermaid in the film.
The pixie's fiery personality was also developed in animation--not so far from Barrie's original descriptions, in fact.
|Roy Best, 1937. Tinker Bell as drawn by a pin-up artist is less of a pin-up girl than Disney's version.|
As to why Barrie included a fairy in Peter Pan to begin with, reasons are numerous. Barrie's work was influenced by the folk tales of his native Scotland, and "Kensington Garden" by Thomas Tickell, written in 1722, is frequently cited as the inspiration for the setting of Barrie's entire fairy world of Kensington Park.
In 1901, Barrie and the Llewellyn David boys were enchanted by Seymour Hicks's theatrical hit Bluebell in Fairyland, which they went to see together during Christmas time.
And specifically, in Barrie's dedication "To the Five," he writes, "As our lanterns twinkled among the leaves [Michael] saw a twinkle stand still for a moment and he waved his foot gaily to it, thus creating Tink."
Special thanks to www.rarestkindofbest.com and the (sadly) largely inactive www.jmbarrie.co.uk for information used in this post.