The Swan by Elizabeth Egloff

Dora Hand lives by herself in a suburb on the Nebraska prairie. She's gone through three husbands and now seems destined to play the lonely mistress to her married milkman, Kevin until a swan crashes into her living room window setting Dora on a harrowing journey. All at once, Dora finds herself dangerously entangled with the swan who, to all outward appearances is a charismatic and child-like man, and whose animal devotion to her threatens her already neglected lover and ultimately her sense of self.