The Sound of Us by Sarah Willis

Alice Marlowe accepts her life the way it is. She is single, lives with a cat called Sampson, and has imaginary conversations with her dead twin brother. As a sign language interpreter for the deaf, she is used to standing between people, facilitating their conversations with each other. But then a late night phone call brings a beautiful, scared six-year-old girl into her life. And seeing herself through a child's eyes for the first time, she discovers that love is a universal language.