When members of the DuPage County Bar Association voted for Lynn C. Cavallo as third vice president in 2011, they knew they were getting a passionate, calculated risk-taker. What else do you call someone who joins the state’s attorney office nearly two decades out of law school? Cavallo, who was installed as the DCBA’s 134th president last week, spent the first 17 years of her legal career as a sole practitioner working on real estate and probate matters. “I was personally and professionally …