Robbie Williams and Ayda Field are very private when it comes to their children.
In fact, the couple only announced they were having a third child when little Coco was born.
Therefore, fans were surprised to learn that their four-year-old, Charlie had been ill.
Ayda revealed the news when she and Robbie attended the Pride of Britain Awards yesterday.
The couple presented three-year-old, Ella Chadwick with the Child of Courage award.
Ella had bravely battled a rare kidney disease, and whilst Charlie's illness wasn't as serious as the little girls, Ayda opened up about how difficult the time was.
Addressing the room on stage, the 39-year-old said: "My son's had health problems. Nothing as serious as Ella's, but when your child is ill you feel so vulnerable, so powerless. Nothing else in the world matters until they're well again."
The mum-of-three added that she understood and related to Ella's mum's struggle and fear of having a sick child.
"So I really felt Ella's mum's worry and pain. To see Ella so strong, sweet, selfless and cheeky, is so uplifting," she said.
Charlie is their middle child, and he has a two-month-old sister, Colette Josephine Williams and an older sister, Theodora Rose, who is six.
Theodora has recently been in the limelight as she was a bridesmaid for Princess Eugenie royal vows to Jack Brooksbank.
The six-year-old has strikingly similar features to her rockstar daddy, Robbie.
Ayda gushed to the Mirror, that little Teddy did an "amazing" job at the wedding.