As the mother of a toddler, Diana Reul-Shapiro was looking for part-time work that she could do at home. Her sister-in-law in New Jersey told her about Macaroni Kid, a growing network of Publisher Moms who produce e-newsletters for families. A stay-at-home mother, Reul-Shapiro, alongside friend Autumn Spear, looked into it a year ago. Today,…