Everybody knows the nuns run this corner of Oak Park. There is Sister Jane, telling a young mother that she needs to make a doctor appointment, today. Nearby, Sister Judy makes sure another woman is served a healthy breakfast. And Sister Esther, though officially retired five years, assists in the Wellspring office on Fourth Avenue. Together, the three nuns helping the poor have served in the Catholic Church for 156 years. "They're good women, pillars," says Deena Smith, a regular at the drop-in center that provides free breakfasts for neighborhood women and children. What many don't know, and what has...