The Good Sister by Sally Hepworth

Publisher's Synopsis

There's only been one time that Rose couldn't stop me from doing the wrong thing and that was a mistake that will haunt me for the rest of my life.

Fern Castle works in her local library. She has dinner with her twin sister Rose three nights a week. And she avoids crowds, bright lights and loud noises as much as possible. Fern has a carefully structured life and disrupting her routine can be...dangerous.

When Rose discovers that she cannot get pregnant, Fern sees her chance to pay her sister back for everything Rose has done for her. Fern can have a baby for Rose. She just needs to find a father. Simple.

Fern's mission will shake the foundations of the life she has carefully built for herself and stir up dark secrets from the past, in this quirky, rich and shocking story of what families keep hidden.