F.A.Q.s by Allegra Goodman, describe the state of Melanie and Dan’s marriage.

Dan and Melanie's marriage is fraught with arguments and fighting. Neither parent seems happy, they merely seem to be resigned to stay married. They are both anxious about their daughter's emotional/ physical health.

Her bedroom had been preternaturally still. Not a rustle, not a breath had escaped the cracks around the door. What if she had done something? Taken something? Drugged herself to disappear?

Phoebe heard all their arguments.

"..... Phoebe remembered how her parents fought when she was little. Once her father had told her mother, "If you're that unhappy, leave."