I've read stories like this before, and the siblings usually are very close. But in this one, they all were as far apart as 4 people raised in the same house could be.
From the cover:
The children of a once-brilliant playwright and a struggling actress, the four Haas siblings grew up in chaos- raised in an environment composed of neglect and glamor in equal measure. When their father dies, they must depend on their intense but fragile bond to remember what it means to be family despite years of anger and hurt. These brothers and sisters are painfully human, sometimes selfish, and almost always making the wrong decisions, but their endearing struggles provide laughter through tears- something anyone who's ever had a sibling can relate to.