Ashlee Simpson Is Now a Mom of Two!

Congratulations to Ashlee Simpson! The singer gave birth to a baby girl on Thursday, July 30, a source confirms to People. The newborn daughter is Simpson's second child and her first with husband Evan Ross.

The couple tied the knot last August and in December announced that they were expecting a child together. Simpson shared the news early with her 6-year-old son Bronx Mowgli (dad is Fall Out Boy's Pete Wentz), who was thrilled about becoming a big brother. "He's excited. He's so excited," she told E! News earlier this year. "He's excited that it's a girl, he thinks it's cute—the tea parties, she'll be adorable."

Simpson kept up with a workout routine during her pregnancy, so we imagine the mother of two will be running around with her little ones in no time.

PHOTOS: The Best Celebrity Maternity Street Style Looks