Alba announced the birth of daughter Haven via Facebook over the weekend, while Fey's daughter Penelope was born last Wednesday.

Honor has a baby sister. Jessica Alba announced on Facebook that she had given birth to her second child, a girl, on Saturday.

"Hope you're enjoying the weekend," she wrote. "Cash and I are so excited to announce the birth of our daughter, Haven Garner Warren. She was born on Saturday, weighed 7 lbs, and was 19 inches long. Healthy and happy! Big Sister Honor couldn't be more excited about the new addition to our family. Thank you for all of your support during my pregnancy. It means the world to me."

Back in February, Alba announced her pregnancy in a similar way, sharing with her fans that she and her husband, Cash Warren, were expanding their family. The couple married in 2008. Their other daughter, Honor, is 3.

Alba is playing a mom on the big screen this week in Robert Rodriguez's latest installment in the "Spy Kids" franchise, "Spy Kids: All the Time in the World 4D." She appeared at the film's Los Angeles premiere on July 31 and has been making the rounds promoting the film, which opens this weekend.

Hollywood's mini-baby boom continued when "30 Rock" star Tina Fey announced over the weekend that she had given birth to her second child, Penelope Athena Richmond, last Wednesday, according to People.com. It's her second daughter with her composer husband, Jeffrey Richmond. The couple has a 5-year-old daughter named Alice. Fey announced her big baby news on "The Oprah Winfrey Show" in April.

"My husband and I really decided that we felt rather than risk having '30 Rock' end in several years and feeling like part of our family is missing that we were going to prioritize our family," she said of the decision to have another baby.

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