When Mary Clare Bonaccorsi became Polsinelli’s managing partner in Chicago, she joined the 20 percent.That statistic refers to the most updated percentage of female office managing partners in law firms, according to a 2018 study by the National Association of Women Lawyers.“Despite universal adoption of women’s initiatives, a ramping up of broader diversity initiatives and increased awareness of the challenges women face in their advancement through the law firm, there has been little progress made in …