With sophistication and restraint, ‘My Little Sister’ tells an engrossing tale of sibling love Ann Hornaday Rating: (3 stars) In the absorbing domestic drama “My Little Sister,” Nina Hoss plays Lisa, a Berlin playwright, wife and mother who is trying to save her brother s life. Sven (Lars Eidinger) is a renowned theater actor best known for his 300-plus renditions of “Hamlet.” As the movie opens, he is suffering from cancer and Lisa has just donated bone marrow for a transplant. To continue to be or to cease being is just one question animating this elegantly constructed meditation on family, identity, filial boundaries and ethical obligation. Written and directed by Stéphanie Chuat and Véronique Reymond with superb control and insight, “My Little Sister” never goes precisely where the audience expects, as the filmmakers dole out crucial information at well-timed intervals, illuminating the pieces of Lisa and Sven’s past that h