Chan graduated from medical school at the University of California, San Francisco, on Monday, the same day Zuckerberg turned 28, the person said. The couple met at Harvard and have been together for more than nine years, the person said. Ms. Chan was born on Feb. 24, 1985, and moved with her family to Braintree, Mass., when she was a junior in high school, according to a recent article in The Patriot Ledger, a local newspaper. In 2003, she was named valedictorian at Quincy High School. Dennis Chan has identified himself as the father of Priscilla and of two other daughters, Michelle and Elaine. Ms. Chan graduated from Harvard in 2007 with an undergraduate degree in biology.