In a tweet, the two-time Olympic gold medallist announced the arrival of Kepaleli Tava Sydney Adams-Price into the world, a baby brother to Kimoana.
The arrival came a little early; Adams' due date was April.
Dame Valerie, who was training as recently as February, previously said she wanted to compete at the 2020 Tokyo Olympics - her fifth games appearance if she makes it.
In December, the 34-year-old said she felt she would still have enough time to prepare for Tokyo after the birth of her boy in April.