But the X Factor winner, 37, insisted the name has nothing to do with pop star Miley Cyrus.
READ: SAM BAILEY OPENS UP ABOUT TERRIFYING PREGNANCY SCARE: "I WAS SO FRIGHTENED"
She's already got nine-year-old daughter Brooke and son Tommy, 5, but Sam said she's always wanted a third child.
Talking to a British magazine, Sam said: "I always wanted three kids, but before The X Factor we couldn't afford it. So I was resigned to the fact I would just have two.
"Then next thing you know I find out I'm pregnant and I was like, 'Yes. I'm finally going to get my wish.'"
READ: JESSICA SIMPSON SAYS THERE ARE NO MORE KIDS ON THE CARDS
Sam's baby girl's full name is Miley Beau Pearson and, aside from her singer mum, she's got a very famous connection.
Sam continued: "Never in a million years did I imagine I'd be having a baby whose godmother is Sharon Osborne."
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In the interview Sam also revealed she almost had some complications during her pregnancy, adding: "I got told at 29 weeks that I had a 70% chance of having the baby in the next couple of weeks.
"So I bought a load of premature-baby clothes and every day I woke up thinking, 'Am I going to have the baby today?
"I was in hospital at about 31 weeks for a few days because I went into early labour and had to have a steroid injection."