The 39-year-old X-Factor judge and her partner Kris Smith welcomed son Ethan last year, and she revealed that she had no idea how much she would learn from becoming a mum.
She told Marie Claire magazine, 'It has always riled me when I hear someone say 'Oh, so you don't have a career, you are just a mother!' It is the most important career you could have! I love it when other parents come up to me and say 'Welcome to the club.'
'The great thing is you have to be a parent to understand all the things you have ever heard about being a parent. I suddenly have a deep understanding of how a mum feels when you have to go to work and your little one is not well.
'Your whole being just wants to be with them to make everything better - that's hard. But the good thing is that I can take him with me. He's with me in the dressing room, so it's not like I don't see him for seven days a week, which I couldn't bear.'