What is Nora's perception of Penny in the novel, The Husbands?

The more Nora learns about Penny's story, the more confused she feels. At times Penny appears to have motives for killing her husband. At other times, Penny seems overwhelmed by grief. At still other times, Penny appears mentally unstable and prone to dramatic public outbursts. Unable to reconcile these competing versions of reality, Nora relies upon what Cornelia, Alexis, and Thea tell her.