Jamie Lynn Spears is a mom of two.
"We are beyond excited to welcome this beautiful baby girl to our family," Spears said in a statement.
"Her middle name, Joan, is to honor my Aunt Sandra, who passed away 10 years ago from ovarian cancer," she added. "She was the most graceful woman I've ever known."
Spears confirmed the news in a tweet Thursday, writing, "Baby Ivey Joan Watson is here." The star already shares 9-year-old daughter Maddie Briann with ex-fiance Casey Aldridge.
Spears, the younger sister of singer Britney Spears, had announced her second pregnancy in December.
"Looks like we are starting off 2018 with another big milestone...sooo happy to announce that Maddie is FINALLY going to be a big sister," she said at the time.
Spears gave thanks for her family in February on the one-year anniversary of Maddie's ATV crash.
She said it was a "miracle" her daughter recovered after nearly drowning after driving her ATV into a pond while trying to avoid a ditch.
Jamie Lynn Spears/Instagram