“We’ve been blessed with the safe arrival of a baby girl,” she wrote alongside a photo of herself holding her newborn’s hand.
“Our family is now complete.”
Piper has not yet shared her newborn daughter’s name.
She revealed she was expecting her second child on Father’s Day 2017.
Posting a photo of her clutching her bump, she wrote: “I’m so excited to tell you all next Father’s Day my husband will be celebrating with two children.”
Speaking about her second pregnancy, Piper told Hello at the time: “Becoming a mum has enriched my life in ways I never imagined and I feel so thankful to be experiencing that again.”
She also revealed she and her husband had been trying for another child for 18 months, adding: “I’ve been asked so many times if we were planning to have another child, but that’s such a private and emotional thing when you’re going through it.”
Piper recently spoke out about how her midwife supported her after the birth of her first child.
In a vlog for HuffPost UK, she said: “All through my [first] pregnancy my midwife really supported me,” she said.
“The moment I came out of that theatre I was in the midwives’ hands, it was a surreal experience. The midwife was next to me when the baby was in my arms and I thought she was just sat there being nice and now I realise she was sat there helping me bond at that crucial time
“Had that midwife thought ‘my shift over I am going’, I wonder whether I would have known how to breastfeed.”