Vandenberg grew up in Moraga, California, and swam for Campolindo High School and Orinda Aquatics. She was a member of the bronze medal-winning U.S. team in the women's 4×200-meter freestyle relay at the 2008 Summer Olympics in Beijing. She also won silver medals at the 2005 World University Games, and at the 2007 World Swimming Championships in the women's 200-meter butterfly. Four years later, she won a gold medal in the same event at the 2011 Pan American Games in Guadalajara.