Sisters of the Midnight Sun by Fiona Valpy

Ruby has come to the Shetland Islands to be a companion to an older lady named Hanna. Hanna runs her farm, Igdrasil, on her own, but is getting on in age and needs help around the farm. Ruby is also coming to terms with the death of her sister, Lucy. As Ruby and Hanna get to know one another, they discover they both have twin sisters. Hanna begins to tell Ruby the story of her life--growing up in Norway,  and what happened in her hometown of Narvik as it was invaded by the Nazis during World War II. Hanna's past story is alternated with the contemporary story of Ruby's time at Igdrasil with Hanna. A notable addition to the genre of women's historical fiction for it's depiction of Norway and its' people during wartime. Readalikes include Jennifer Robson and The French Gift by Kirsty Manning.