Where does the point of attack begin in the play Rabbit Hole by David Lindsay-Abaire?

The point of attack in a play is a reference to the moment the play begins. There are essentially two types of points of attack. The first is the early point of attack, where events unfold organically, and we are able to witness the events as they happen. The second is the late point of attack, where the play begins after tumultuous events that occurred in the past.
In the late point of attack, the play begins long after the story begins. In Rabbit Hole, the point of attack is eight months after the death of Becca and Howie's four-year-old son, Danny. When the play begins, Becca is in conversation with Izzy, her sister. The sisters are quarreling, with Becca clearly angry at Izzy for engaging in a physical altercation with another woman at a bar. It eventually turns out that the woman had been upset when she discovered that her former boyfriend, Auggie, had gotten Izzy pregnant.
As the play unfolds, we learn Becca has been washing all of her deceased son's clothes in preparation for giving them away to Goodwill. Becca offers Izzy the clothes in case she has a baby boy. The clothes look like they will fit at least a three-year-old child. Izzy is uncomfortable with the prospect of dressing her baby in her dead nephew's clothes, even if the baby turns out to be a boy. She declines Becca's offer, and the play soon moves to an exchange between Becca and her husband, Howie.
Becca and Howie discuss Izzy's pregnancy, but the conversation is fraught with emotional conflict. Becca obviously feels ambivalent about her sister being pregnant, and she finds the topic of new babies difficult. The conversation soon turns to Danny's death and how different members of the family on both sides have coped with it. Eventually, we learn Becca and Howie have not been sexually intimate for eight months, essentially since the death of their four-year-old son. While Howie wants to begin to heal and try to move past their loss, Becca is hesitant.
On some level, Becca thinks enjoying a measure of intimacy with Howie would be a betrayal of Danny. For his part, Howie sees that his wife is hurting, and he wants to help. Becca is too upset to see any value in his efforts. She thinks they should move, but Howie would prefer Becca see a therapist to help her deal with her grief. The story began long before the play itself. The story centers on the events surrounding Danny's death, although the play begins eight months after Danny's death (this is the point of attack). The play itself documents Howie and Becca's journey through the healing process.
Source: The Architecture of Story: A Technical Guide for the Dramatic Writer by Will Dunne.