The couple have called the tot Maddie Briann.
'Just the family was there,' a source tells People. 'Everyone is healthy and happy.'
The 17-year-old actress checked herself into Mississippi Southwest Regional Medical Center at 2am this morning.
It is thought her Caesareans had been scheduled for today and that the baby was born at around 9am.
Older sister Britney, 26, mum Lynne and brother Bryan turned up at the hospital a few hours ago.
Jamie Lynn announced she was expecting a baby in December.
Where to next?
- All you need to know about Caesareans
- Can I choose a Caesarean?
- How safe is a Caesarean?