"My mum was a bit concerned," the Nine journalist told Essential Baby. "All she thought of when she heard Darcy was the famous 1940s Australian bank robber and criminal Darcy Dugan!"
However the 2GB Afternoons host stuck by her love of the name and went ahead with the choice.
"We chose the name Darcy as it's a classic name that has real strength to it and who is not a fan of Mr Darcy in Pride and Prejudice?"
Knight and her husband Lindsay Dunbar continued to look to classic names for inspiration when naming their daughters as well, choosing Elsa for their second child.
"We named Elsa well before the Disney film came out - just to clarify!" Knight joked, saying they had originally planned on naming her Alice.
"But Elsa just suited our little bub when she arrived," she continued. "Again - it's a classic name and is very sweet."
When their third daughter came along, the couple already had a gorgeous timeless name in mind.
"My grandmother was named Audrey and I've always loved the name," the mother-of-three explained. "It means 'noble strength' - and I think it suits our Audrey perfectly."