Callie was born in the city of Canterbury, England, to Eric Quinn and Anabelle Quinn. Her parents were best friends with Ferb's parents, so on her 4th birthday they came over to celebrate and brought Ferb. When Callie opened her gift from the Fletchers, she instantly fell in love with the bike. She went outside to play with it with Ferb. She let it go for a moment and it rolled into the street. After the bike was crushed by a car, Callie was devastated. Ferb ran to his house next door and grabbed his tool kit. He fixed her bike, and they became best friends, swearing they'd always stick together. Callie loved Ferb's building, and felt like he was the only person she didn't need to be shy around. They played with each other everyday, causing there friendship to grow stronger.