The 32-year-old singer says she temporarily lost her voice and truly believed that her singing career was over.
"Afterwards was the part where I literally had a moment where I cried and drank wine all day," she admits. "I was like, 'Oh, God, I'm not going to be a singer anymore!' I was bawling to my husband and like, completely hammered, just going, 'Oh my God, it's over, I don't know what I'm going to do. I guess I could do more charity work.' Like, I didn't know what I was going to do."
But Kelly surprisingly reveals that she actually didn't have the desire for motherhood before meeting Brandon.
"You know what? I never wanted to be a mom," she says. "I didn't think I had that maternal thing happening. I'm very much a gypsy at heart and didn't think I'd get married."
Clearly, things have changed significantly. Kelly and Brandon, a talent manager, have been married since October 2013.
"I'm annoyed by my previous self," she told Radio 1 Breakfast Show's Nick Grimshaw last month about how motherhood has changed her. "You have a baby and realize you worried about stupid stuff. I didn't like me before, but I like me now."