Jessica Simpson is "doing really well" following the birth of her daughter.

Jessica Simpson

Jessica Simpson

The 38-year-old singer and actress welcomed her third child, a daughter name Birdie Mae, into the world earlier this week, and sources say she's "feeling good" following the birth and is "savouring every minute" with her new bundle of joy.

An insider told People magazine: "Jessica is feeling good. The baby is doing really well. Birdie is perfect and Jessica is savouring every minute. Her family has been back to visit at the hospital and they are elated. They are just soaking it all in."

The news comes after Jessica - who also has daughter Maxwell, six, and Ace, five, with her husband Eric Johnson - confirmed the birth of Birdie this week, when she shared a picture of Maxwell meeting her little sister.

Jessica wrote: "We are so happy and proud to announce the birth of our perfect daughter, Birdie Mae Johnson."

And insiders recently said the 'Blonde Ambition' star's older children are "so excited" to be big siblings.

One source said: "Maxwell was hoping to maintain her record of the biggest baby in the family [at 9 lbs., 13 oz.], and now Birdie has her beat by 1 lb. She's so in love with her little sister. Everyone is very happy."

Meanwhile, although she's happy to be a mother of three now, Jessica previously revealed she had no idea how she'd managed to get pregnant again.

She said: "I thought about [having another baby], but I didn't really know that it could actually happen. We definitely always love to practice. We actually weren't practicing very much that month so I don't understand. We try [to figure it out]. This might be a miracle baby."