Bristol Palin announced Thursday that she had given birth to her second child, a girl named Sailor Grace, the day before.
Palin, the daughter of former governor and vice presidential nominee Sarah Palin, broke the news on Instagram.
Family attorney John Tiemessen said he could confirm only that the Instagram account is Bristol Palin's.
Palin was an 18-year-old unwed mother when she launched an abstinence campaign soon after giving birth to a son, Tripp, in December 2008.
She was engaged to Medal of Honor recipient Dakota Meyer but the wedding was called off days before the ceremony earlier this year.