The star of '90s hit Curly Sue and husband Brian Autenrieth welcomed a son, Mason Blaise Autenrieth, on Tuesday, July 17 in the Los Angeles area, the couple confirm exclusively to PEOPLE.
Mason arrived at 5:20 p.m., weighed in at 7 lbs. and is 20 inches long. "We are all very in love," Porter Tweets, sharing a photo of her husband's daughter Cassie holding her new baby brother.
The singer-songwriter and actress, 31, got ready for her little bundle of joy with a baby shower last month in Agoura Hills, Calif.
"It was a perfect day," Porter told PEOPLE at the time. "I couldn't have imagined anything more beautiful. There was so much love."
She married Autenreith, 34, in March in an intimate ceremony at a historic ranch nestled in the Santa Monica Mountains.