JK Rowling has given birth to a baby girl. The girl, who hasn't yet been named, was born on the evening of 23 January.
A spokesperson for JK told CBBC Newsround Online that "both parents are thrilled" about the birth. Both JK and the baby are said to be doing well.
The baby was born on Sunday night in Edinburgh's Royal Infirmary.
JK has now been discharged and is at home with her baby and the rest of her family.
The author married Neil Murray on Boxing Day 2001 and this is their second child. Their first, David, will be two years old in March.
JK already has a 11-year-old daughter, Jessica from a previous marriage. In the past she has said that she always wanted three children.
More information will follow on JK's official website. The next Potter book, The Half-Blood Prince is due out on 16 July 2005.
Congratulations JK! I hope she will be as talented as you!
Jessica, 13, Jersey
Congratulations JK! I've enjoyed all your books and movies and await the arrival of the Half blood Prince! Hope the little baby likes your books as well!!
Reem, 10, Haywards Heath
Congratulations on the birth of your baby daughter, have a great year and I can't wait until the next Harry potter book! Thanks for writing them and again congratulations.xxx
Rebecca, 15, Birmingham
I think her daughter will be proud. Her mum is such a gr8 author! Maybe she will be a good author too!
Maddie, 12, London
Congrats JK!!!! I hope you and your family are enjoying the new baby and wish you the best of health!
Leigh, 14, East Kilbride
Congratulations JK! Let us all know when you've got a name for her.
Rachel, 13, Glasgow
Congratutions JK!! Wish you all the best and I hope she loves Harry Potter as much as you do!
Tulsi, 11, Walsall
Congratz! We'd all love to hear her name, maybe Hermione?!
Alice, 11, Ipswich
Congrats! I hope you're very happy with your new little girl, and I wish you all the luck in the future!
Sentry, 12, Sutton
Awh!!! I'm sooooo happy for you! I wish you the best of luck and hope she brings you all the happiness in the world!
Sara, 14, Belfast
WOW!! Congratulations Jo!!!!!! Best wishes to you and your daughter!!
Ailish, 13, Northallerton
Congratulations JK!! Will be thinking of you and your new baby girl! P.S. It would be funny if you called her Hermione!!
Suzi, 15, N. Ireland
Many congratulations and I wish you all the best!
Lucia, 14, Spain
Congratulations! I hope she is well and happy and that she grows up to write fab books like her mum!
Flo, 12, Berkeley
Congrats! I wish you and your family the best of luck, especially the new baby.
Cecilia, 15, Croydon
Congratulations! And good luck! I'm loving the Harry series so far and really really can't wait 173 days!!!!!!!!
Tabatha, 13, New Barnet
CONGRATULATIONS JK!!! I'm thrilled, as well as your fan!! I hope you're still enjoying writing as the fans love reading it. I hope your daughter and your children loves it as well!!
Savitri, 14, London
Congratulations JK!!!! I wonder if you will name your new baby girl after one of your characters??
Phelim, 11, Guildford
Congratulations JK! I hope your new baby girl enjoys all the Harry Potter books as much as we do when she's older!
Sam, 13, Manchester