“She and Freddie are thrilled,” a source close to Gellar told People.com.
The couple has a 2-year-old daughter, Charlotte Grace, who was born in September 2009.
The source said, “They love their little girl more than anything in the world and know that love will only multiply. She is such a fantastic mom; it is just great news.”
Gellar, 35, and Prinze Jr., 36, were married in 2002.
Actress Sarah Michelle Gellar and husband Freddie Prinze Jr. are expecting their second child.