Who is Barbara Berstein from Presumed Innocent and what is their importance?

Barbara Bernstein is Rusty's wife and the mother of their son. Like many other characters in this novel, Barbara is unusually intelligent. A mathematics whiz, she goes back to college after the birth of her son to get a doctorate in math. Her habits are meticulous where she keeps everything in place, and is deeply interested in intellectual pursuits of many descriptions. For fun, she reads books on all sorts of arcane subjects. Her devotion to Rusty and their son is absolute. When Rusty engages in an affair and later confesses to Barbara, her bitterness is intense. She disengages from him emotionally and physically and picks him apart verbally every night with sarcasm and insult.