Diane graduated from the University of Illinois and taught in the Chicago public school system for several years. She joined Leff, Klein and Kalfen in 1986. With the guidance of her late husband, Joel Klein, her brother Alan Leff, and David Kalfen, she became an asset to the company in bookkeeping and accounting. Diane works with a variety of clients, including manufacturers, restaurants, and service professionals. Her responsibilities include assisting clients by preparing financial statements through bank reconciliations, check coding, creating journal entries, and processing this work in accounting software programs. She also prepares sales tax returns, payroll tax returns, and annual forms for W-2 and 1099 reporting. In addition to client responsibilities, Diane plays an important role for the firm's internal accounting and management needs.