The illustrator is none other than Nina Dulleck.
The book "Brilli, das Küken", illustrated by her, was awarded the International Dyslexia Quality Award in 2010. 2011 became "Glück gesucht" in Austria to the "Bücherliebling 2011". The cover of "The Little Lady" was chosen by Librikon as one of the five most beautiful covers of the year 2010.
Check out some of her work here.