Before You Know Kindness by Chris Bohjalian

Nan Seton is a widowed, wealthy, and endlessly energetic matriarch who spends her winters in her large apartment in Manhattan and her summers in the family home in New Hampshire. Every summer, Nan invites her son and daughter, John and Catherine, along with their spouses and children, to spend some time with her. Under Nan's direction, the family participates in an endless and dizzying round of athletic and social activities.

The book opens with a horrifying scene in which Spencer McCullough, Nan Seton's son-in-law, is accidentally shot in the shoulder, and very nearly killed. Spencer is an animal rights activist. Whether he is forcing inedible foods down his family's throats or insisting that his relatives wear plastic shoes, not leather, Spencer is unyielding in his insistence that no living thing with a parent should be a source of food or clothing for human beings. Spencer's overbearing personality and frequent absences from home have already alienated his wife, Catherine, who is ready to give up on her marriage.

After the shooting, the entire family goes into shock. This event shakes up everyone's comfortable assumptions about their lives and one another, and it forces them to reevaluate what is really important to them.