If you want to do the best for your child, then first try trusting your own instinct.

That's the expert opinion of nanny Kathryn Mewes, who says the biggest modern parenting problem is simply parents feeling unable to put faith in their own gut instinct about how to bring up their children.

Mewes is starring in a new series of Channel 4's The Three Day Nanny, where she visits family homes for three days and helps them tackle various problems with their children.

Her experiences with families on the show and other clients has led her to conclude: "Children aren't being raised by parental instinct, they're being raised via Google, chatrooms, TV shows, books, magazines and other people's opinions.

"I think parents are losing instinct - there aren't many who are strong enough to say that something works for their family so stuff what everyone else is saying.

"I think that's what's making parenting so hard."

In the new series, Mewes deals with a family where the kids are running riot because the mum's lost her confidence and the dad's more concerned with checking his smartphone; a single nursery school teacher mum who's imposed such a strict regime on her kids that Mewes counts 72 rules in just her first few hours in the house; and a family where the three-year-old daughter rules the household.

"It's gone beyond not trusting their own instincts," explains Mewes. "The parents who reach out for me have lost all their confidence and belief in themselves."

She explains that the problem often boils down to control, with parents either trying to control children too much so they rebel, or children themselves being in control and the parents not knowing how to regain it.

"It's about listening and understanding one another, giving your child responsibility, so they can have some control, but the parents also assessing where they need to have control, and staying true to it."

Mewes, who's written a Three Day Nanny book to accompany the TV series, says the key to improving vital aspects of life with children, such as eating, sleeping and behaviour, usually involves consistent routines, and the parent remaining in control.

She stresses: "I don't believe in naughty spots and naughty behaviour. It's fine to get angry, but what's important is you don't get angry with people, and you remove yourself from a situation and sort yourself out.

"Anger is normal and you don't have to control it, you need to learn how to manage it."

Mewes sometimes suggests having anger spots or shout spots in houses, where all family members might go to let off steam or calm down.

"I don't believe in a house having children's rules and adults' rules," she says.

"I think there should just be family rules."

Mewes says families often say they didn't realise they'd be paying her for common sense.

"I always say if the sense I gave them was that common, they wouldn't have rung me.

"When I explain things, parents say it all sounds so easy and logical, why didn't they see it? There's a lot of kicking themselves."

And kicking is something Mewes herself knows a lot about at the moment, as she's expecting her first baby in August.

But the excited mum-to-be admits that while she may be an expert on the practicalities of child-rearing, the emotional side is a complete unknown to her.

"I do feel amazed, standing here looking at my bump, that I'm 41 and my body's let this happen," she says.

"I'm very nervous - I hope and pray that I'm not going to be a parent that always says yes.

"I look at parents and they're an emotional wreck, and I wonder how a tiny child's done this to them. So for me there's a huge question about this emotional pull that I know nothing about.

"I'm ready to get on the emotional roller coaster."

But where does the expert turn to for advice?

"If I need advice, I'll go to my mum - we have such a strong relationship that if I feel she's judging me for one minute, I'll tell her and we'll be fine."

And she adds: "What I try to bring back into every home I go into is instinct. I'll just say to them I'm not the manual, first use your instinct and then ring me. Give it a go with your guts, and if you feel it's not working, we'll see what my gut says.

"A lot of it's just about reassurance, and what's wrong with that?"

:: The Three Day Nanny starts on Channel 4 on Tuesday, July 28

:: The Three Day Nanny: Your Toddler Problems Solved by Kathryn Mewes is published by Vermilion, £12.99. Available now.

ASK THE EXPERT

Q: "My daughter is refusing to brush her teeth, or just brushes quickly. How do I get her to brush properly without constantly watching her?"

A: Dentist Dr Henry Clover says: "Brushing effectively is a skill that with plenty of tuition and practice, your child will soon learn to do independently.

"Brush your teeth with your daughter to show her what to do and help her overcome common mistakes like brushing too fast or too hard.

"Brushing for two minutes can feel like a long time and it's common for children to rush. To help her brush for the recommended duration, encourage her to brush along to her favourite song. Some teeth can be hard to reach, so try encouraging her to roar like a lion and open her mouth wide when brushing.

"Much like adults, children can sometimes find brushing a chore. Help them enjoy brushing their teeth by equipping them with a fun toothbrush and toothpaste that they like the flavour of. Remember, children will need to use age-appropriate toothpaste that shouldn't be rinsed off, as this can wash away the protective fluoride.

"A great way to measure how much progress your children have made in learning to care for their teeth is to encourage them to record their tooth brushing on a chart. Not only does this make brushing fun, it also helps children to build brushing their teeth into their daily routine. If you're still struggling, Denplan's Little Book of Healthy Smiles has tips to help keep tooth brushing interesting."

:: The Little Book of Healthy Smiles can be downloaded from www.denplan.co.uk/my-teeth/childrens-teeth/big-summer-brush-up-patients.

POOL PALS

Pink Flamingo Pool Float

Mum and dad will always be able to see where the kids are when they're playing in the pool with this 4ft inflatable vinyl float, which includes a patch repair kit. £23.95, www.prezzybox.com

Splash About Kayla La Swimming Costume

A strappy designer costume with pretty flower detail in super-soft material. Part of a range of mix-and-match holiday wear. Available in sizes from six months to eight years. £13.31, www.splashabout.com

Zoggs Kids' Dive Sticks

Brightly coloured weighted sticks which sink slowly in the pool and sit vertically on the bottom so they can be grabbed easily to help children get more confident swimming underwater. Suitable from age three plus, and only to be used under adult supervision, a pack of four sticks comes in a handy zip bag. £9.59, www.amazon.co.uk