What do the other characters call Astrid's house in the novel, All Adults Here?

The Big House is what the novel’s characters call Astrid’s house, a three-story stone mansion. Astrid purchased the house with her husband Russell, who has been deceased for many years. At the start of the novel, Astrid is living in the Big House by herself, but Cecelia, who has been sent to live with Astrid from New York City, soon arrives. The house is the site of several notable events during the novel, including a weekend brunch at which Astrid announces her relationship with Birdie to her children and several family dinners.