Her birthday was on July 2nd.
Born in The Hague, Holland, she has lived in Stuttgart, Germany since 1964.

http://www.google.com/search?tbm=isch&hl=en&source=hp&q=arnica+esterl&gbv=2&oq=arnica+esterl&gs_l=img.3..0j0i22i30l4.844.844.0.1875.1.1.0.0.0.0.63.63.1.1.0...0.0...1ac.1.15.img.V8YwHMXFLpU
(photos & book covers)

http://www.worldcat.org/identities/lccn-n91-1154
(booklist - mostly Andersen tales)

https://www.goodreads.com/author/list/78926.Arnica_Esterl
(reader reviews - some are in English)

https://de.wikipedia.org/wiki/Arnica_Esterl
(in German, with long booklist)

Translation (in part):

"Arnica Esterl spent her childhood on a West Frisian farm. She completed an apprenticeship as a tailor and later studied German, Frisian and philosophy in Amsterdam and at the University of Tübingen. Since her marriage to the German Waldorf teacher Dietrich Esterl, she has lived permanently in Germany; she has been based in Stuttgart since 1964.

"Arnica Esterl has been dealing with fairy tales both theoretically and as an oral narrator since the 1970s. She has published numerous adaptations of international fairy tales, translated children's books, mainly from Dutch, and worked for radio in the 1990s. Esterl has been a member of the European Fairy Tale Society since 1976 and was one of the co-founders of the Stuttgart Fairy Tale Circle in 1979, of which she chaired from 1989 to 1997."

Books available in English include:

The Fine Round Cake (1991, based on "Johnny-Cake"), illustrated by Andrei Dugin and Olga Dugina

Dragon Feathers, 1993, illustrated by Andrei Dugin and Olga Dugina
("The poor woodcutter's son is sent on a mission to the dark forest to pluck three feathers from the dragon's back. Only then can he marry Beth, the rich innkeeper's beautiful daughter. Along the way, he meets several people in need of his help. But will his kindness and bravery be enough to protect him from the angry dragon?")

Okino and the Whales, 1995, illustrated by Marek Zawadki
("The whales have arrived. As Okino and her son, Takumi, watch the mysterious animals play, she introduces him to the dreamland of Iwa, the Great Mother of the Ocean. Okino tells him of a talking seagull, a magical lantern, and an enchanted palace deep beneath the rolling waves, where a courageous mother once confronted Iwa and was challenged with a task that took years to complete.")