The actress, who played Lavender Brown in the film adaptations of JK Rowling’s books, gave birth to Tenn in October following what she described as a “traumatic birth.”
In a post on Instagram, she said, “Baby is home now. Thank you for all the good wishes and messages of support. ”
Earlier this week, Cave revealed that her “poor baby” had contracted COVID-19[feminine[feminineand was treated at Chelsea and Westminster Hospital.
Posting a photo of Boris Johnson delivering his speech to the nation on Monday night, she wrote: “I watched the lockdown news from an isolated room in the hospital.
“The poor baby is COVID positive. He is doing well and doing well, but fortunately they are vigilant and careful. ”
The star, 33, added: “I really didn’t want this to be the start of my family’s New Year. I really didn’t want to be back in the hospital so soon after her traumatic birth. Once again I am in awe of nurses and doctors. ”
She said the new strain of coronavirus was “super potent and contagious” and warned people to “be very careful”.
Singer Paloma Faith was among those who responded to the post, writing, “Sending so much love to all of you… get one soon and the anxiety is real! God bless the NHS! ”
Model Erin O’Connor sent a series of heart emojis, while podcaster Pandora Sykes said, “Oh Jessie, poor thing – sending love and force x. ”
Cave and his partner, comedian Alfie Brown, have two more children – Donnie, five, and Margot, three.
They initially named their new baby boy Abraham “Bam” Benjamin, but said in December that they had changed his name to Tenn.
Cave said it was delivered 40 minutes after its waters broke.
“It was a very different experience from my first two births… much more humiliating, terrifying and beyond my control,” she said.