Complex sentence: Ms. Jacobs began work at her family's independent insurance agency in 1981 after graduating from Cornell University and, under her leadership, it became one of the top 100 insurance brokers in the United States.
Split into simpler sentences: Ms. Jacobs began work at her family's independent insurance agency in 1981 after graduating from Cornell University. Under her leadership, the company became one of the top 100 insurance brokers in the United States.