Ottilie and its diminutive Ottiline are a pair of names heard among the British upper crust, but have rarely been seen here since the 1880's. Though it has German roots via Otto, Ottilie has a distinctively delicate French feel.
Ottilie does have a few cultural references: She is a key character in Goethe's Elective Affinities, Robert Louis Stevenson wrote a poem called To Ottilie, Franz Kafka had a sister named Ottilie, and it is the name of the protagonist in the John Wyndom sci-fi story Random Quest.
Probably the best known Ottilie is the German journalist, abolitionist and feminist Ottilie Assing, who had a long involvement with fellow abolitionist Frederic Douglass.
Some attractive Ottilie relatives: Ottoline, Ottilia and Odile. And Ottilie has the adorable nicknames of Lottie and Tillie.