"The name of the elite, women-only coworking space stretches across the wall behind the check-in desk: THE HERD, the H-E-R always in purple. In-the-know New Yorkers crawl over each other to apply for membership to this community that prides itself on mentorship and empowerment. Among the hopefuls is Katie Bradley, who's just returned from the Midwest after a stint of book research blew up in her face. Luckily, Katie has an "in," thanks to her sister...