Singer-turned-TV presenter Rochelle Humes talks to Hannah Stephenson about motherhood, marriage, and her foray into the world of children's fiction.

Like other high-profile women who rose to fame in a girl band - Victoria Beckham, Cheryl, Louise Redknapp and Nicole Scherzinger spring to mind - Rochelle Humes has become a master of reinvention.

The Saturdays singer (the group has been on a break since 2014) has shown her mettle as a TV presenter, having filled in for Holly Willoughby on This Morning while Willoughby was in the jungle, become a fashion and beauty brand ambassador, and is set to co-present a new Saturday night music quiz show, The Hit List, with her husband Marvin Humes later this year.

"We've done a tiny bit of work together before, when we've hosted This Morning for the summer, but I'm really excited to be doing our first show together," Humes reveals.

In the meantime, the bubbly 29-year-old has now added another string to her bow with the publication of her debut children's picture book, The Mega Magic Hair Swap! - a story about girls, curls and celebrating difference, which she hopes will be the first of a series.

It's dedicated to her daughters - Alaia-Mai, five, and Valentina Raine, who turns two in March - and tells the story of two young friends. One with big dark curls and one with straight blonde locks, who both dislike their own hair and want to swap.

The characters, Mai and Rose, are based on Alaia-Mai and her best friend, whose middle name is Rose.

"It came about because my daughter was going through this phase where she didn't like her hair, and was noticing the fact that she was a little bit different to her best friend and the friends in her class. It started off with hair and then it was skin colour. She wanted hair like her best friend at school," says Humes.

"I would make up these little stories as mums do - and then The Mega Magic Hair Swap! was born, but with a good moral. I think it's bigger than hair. The moral is to teach kids to be who they are.

"I want all my books to have a moral, to have positive stories for young children and to have every child represented."

Humes, whose parents divorced when she was three, was raised by her mother Roz Wiseman, and says she had times growing up when she felt different from other children.

"Everyone goes through a phase where the grass is greener, but with age you become more comfortable in yourself, from what you look like to how you approach situations. You learn to love and appreciate what you've got."

She was a shy child with a stutter, and says she's still not quite sure why she went into showbiz.

"I had a full-on stutter when I was little and went to speech therapy, and they encouraged my mum to send me to a dance or acting club to bring me out of my shell," she recalls.

"I was the little one who would hide behind my mum's legs in all situations. Now she can't shut me up!"

By the time she joined S Club Juniors aged 12, the stutter had gone and Humes was on the road to fame. But her upbringing kept her grounded, she says, and she's learned a lot about motherhood from her own mum.

"I was brought up with my mum working every hour God sends, and it's important to show children that you have to graft," she reflects. "But do you know what? I'm winging it like everyone else. There's no recipe, no formula. I'm lucky I've got a good support system."

She and ex-JLS singer Marvin, 33, who live in Essex, share childcare duties, with the help of their family network.

"In terms of motherhood, I just treat each day as it comes. Marvin and I sit down on a Sunday and figure out the week. I don't have a nanny. My mum has been a paramedic for so long but has slowed down with that now. I also have a very good babysitter who is nearby."

The couple's careers seem to have run in tandem - both were singers in very successful groups, both have gone on to be TV presenters. They've been together for nine years and married for seven.

So, is there any competition between them?

"He is very competitive but I'm not. He's one of those people who's good at every sport they try. It's really annoying! And I know that I'm not going to be, so I just hold back and say, 'No, I'm fine, you go for it'," Humes shares, laughing.

It's clear they are totally in love.

"It's a funny thing. I'm his biggest cheerleader ever and he's totally mine," says Humes. "When you're in a comfortable relationship, when he's done well, I feel like I've done well myself. We get just as excited as each other."

He has made parenting and navigating a career much easier, she adds.

"I count myself lucky having Marvin. My mum did it on her own, and I think, 'My goodness, we really lean on one another'. I can have a really busy month and then a quiet two months, when I have more time with my kids than my mum ever had with me.

"Alaia came everywhere with me when she was little. She's so adult-like because she was around us for a while until she started nursery. But my mum says to me, 'You never grow out of the guilt', and says she still has it with me now.

"Mum guilt is such a normal thing," Humes continues, "whether you're a working mum or a stay-at-home mum. My friend feels guilty because she's not providing and feels that she's not showing her kids that working is good. That's the nature of being a woman. You just put pressure on yourself every now and again."

As well as co-hosting The Hit List, she'll be co-presenting a new series of Ninja Warrior UK in April, and hopes there are more children's books on the cards. As for whether their family will continue to grow, the Humes' are enjoying life as a foursome for now.

"My youngest isn't even two yet, so it's definitely not on the agenda, but I would never say never," says Humes. "At the minute, I like the fact that we've got two and there are two of us and we can both man-mark a child at a time. There are no plans right now."

The Mega Magic Hair Swap! By Rochelle Humes is published by Studio Press Books on February 7, priced £6.99.