Arrietty (ahr-ee-ET-ee) was a name made famous for the first time by author Mary Norton in her 1952 novel The Borrowers, a story of a family of tiny people living in the house of a normal sized family who "borrow" their supplies from the humans to survive. The name was made famous for the second time when Hayao Miyazaki's animation company, Studio Ghibli, turned the story into a Japanese animated motion picture, called "The Secret World of Arrietty," which was released by Walt Disney Pictures in the U.S. Please note that ahr-ee-ET-ee is the correct pronunciations of the name.
For those of you not familiar with Ghibli movies, including Kiki's Delivery Service, Spirited Away, Totoro and Castle in the Sky (all of which had U.S. releases), these movies are a must see for adults and children alike (says the biggest Ghibli fan ever). There are no American animations that compare when it comes to story and artwork, and you'll find that a recurring theme is protecting the environment - a good lesson for kids to learn. And don't get me started on the music. The songs for Arrietty were written by a Ghibli fan, Cecile Corbel.
Without spoiling too much, the plot of the book and movie is this: Arrietty Clock lives with her mother, Homily, and father, Pod. She meets a human called The Boy, named Sho in the Japanese movie and Shawn, I believe, in the American version. They become friends, but The Boy understands that she should not be seen by others, because it is not safe. Arrietty tells The Boy how there may actually be only a handful of Borrowers left in the world. Both the book and movie have an equal "leave you wanting more" ending.
Arrietty has only experienced a handful of namesakes since the 1952 novel, none born in recent years, and White Pages tells me there are only two living Arrietty's. It seems like Arrietty comes from Arietta, a variant of Arlette, which is a variant of Charlotte, but it is in fact a German variant of Harriet, meaning "home ruler." In other words, Arrietty was not just "made up" by Norton. I definitely see some little Arrietty's being born soon. Especially considering possible nicknames like Ari, Etty and Etta, although Arrietty does feel like a nickname itself.