Making Toast by Roger Rosenblatt sounds like an incredibly moving story...
From the publisher's website:
When his daughter, Amy—a gifted doctor, mother, and wife—collapses and dies from an asymptomatic heart condition, Roger Rosenblatt and his wife, Ginny, leave their home on the South Shore of Long Island to move in with their son-in-law, Harris, and their three young grandchildren: six-year-old Jessica, four-year-old Sammy, and one-year-old James, known as Bubbies. Long past the years of diapers, homework, and recitals, Roger and Ginny—Boppo and Mimi to the kids—quickly reaccustom themselves to the world of small children: bedtime stories, talking toys, playdates, nonstop questions, and non-sequential thought. Though reeling from Amy's death they carry on, reconstructing a family, sustaining one another, and guiding three lively, alert, and tender-hearted children through the pains and confusions of grief. As he marvels at the strength of his son-in-law, a surgeon, and the tenacity and skill of his wife, a former kindergarten teacher, Roger attends each day to "the one household duty I have mastered"—preparing the morning toast perfectly to each child's liking.
With the wit, heart, precision, and depth of understanding that has characterized his work, Roger Rosenblatt peels back the layers on this most personal of losses to create both a tribute to his late daughter and a testament to familial love. The day Amy died, Harris told Ginny and Roger, "It's impossible." Roger's story tells how a family makes the possible of the impossible.