How do you help young girls feel happier?

Selfies, celebrities and social media - there has never been more pressure to look good 24/7.

More than a third of girls aged 10 to 15 years old are unhappy with their appearance and a quarter are unhappy with their lives, a new report from the Children's Society's has found.

While boys' sense of happiness remained stable, girls' happiness has plunged.

So why are girls suffering from low self-esteem and what can we do to make them feel better about themselves?

What advice would you give a younger you?

Nicky Hutchinson, a body image expert who works with schools, said she was surprised that the statistics weren't worse.

"It's just this generation," she said, "you have to promote yourself all the time, it's a PR job."

While people have always been interested in celebrity culture, today's celebrity world is "extreme" she said, pointing to celebrities who advertise their lives on social media or reality TV.

"There's this fake world that they've all created - taking 100 selfies just to get the one good one."

"What's new is that you have to post to everyone - in the past people wouldn't know what party you'd been to but now it's all posted and public - your social life. It's real misery for teenagers."

Social media encourages people to present a personal brand from a young age, and to seek reassurance in the form of likes and shares.

This amounts to "enormous pressure" on girls, says Nick Harrop from the charity YoungMinds.

Therapist and agony aunt Emma Kenny said: "We edit our lives constantly on social media but also we have to look at the deeper-rooted issue - which is the fact that young girls know from a very early age that they are judged on their appearance."

Girls need to know the facts about Photoshopping, that celebrities are being "airbrushed to their very core" and they need to question the images they are seeing.

Ms Hutchinson said girls are relieved when they discover the facts.

She said: "Question advertisements and photos and how real they are. Looking at the stars on the red carpet - ask [girls] how long they thought it took them to get ready."

Having honest images in the house and encouraging conversations about women's aspirations can help dispel the "myth of celebrity", said Mrs Kenny.

She said Photoshopped images are "creating foundations on sand because your looks don't last and actually they're not aspirational".

Ms Hutchinson said: "Parents should tell their daughters about the other parts of them that they appreciate - their sense of humour, or how brave they are.

"It's about letting them know about the good bits about them that are not about how they look."

Ms Hutchinson urges parents to concentrate on girls' qualities and individuality rather than focusing on their appearance - and it is worth starting from a young age.

"I've seen girls aged eight, nine or 10 saying their thighs are too big - it's not just teenagers. Start before they are feeling the pressure of being a teenager," she said.

Girls can learn from a really young age that legs are for running and arms are for lifting, she added, "bodies are for use - and are not ornaments".

Social media is here to stay and it can be a force for good - so there's no point banning it.

But Mrs Kenny says your child will be much happier if you "limit it rigorously".

Girls are spending a lot more time on social media than boys, according to Lucy Capron from the Children's Society: "Up to three hours a night in some cases."

Psychologist Lucy Beresford suggests introducing a family protocol.

Limit time spent on social media, make it a rule that homework has to be done before spending time online, or ban it during mealtimes or on Sunday mornings.

Keep phone chargers out of bedrooms so devices can't be used at night.

"Make it a treat and not a constant", Ms Beresford said.

Ms Beresford said the pressure to be perfect doesn't just come from social media.

She said parents must monitor their own behaviour. "We pick up our way of operating from our family - for example, if you're always going on about your weight - be very careful," she said.

What you say around the dinner table, the messages you send out about your daughter's life and your own life are very important, Ms Beresford said.

She added: "We think we are being kind when we say girls can have it all, but girls can feel a bit scared by that."

Talk to girls about all the options - even if your answer "ends up being three times as long".

Being open for conversation is key - and you can start with the small stuff.

Ms Beresford said: "They need to have proper conversations with you. Have conversations about random stuff - the latest on Justin Beiber, anything, and the serious stuff will follow."

She said people need to be open and available for conversations, no matter how busy or important you are.

YoungMinds' Nick Harrop said parents should take it seriously if their child is consistently anxious, unhappy, angry or withdrawn.

He said: "Let them know you're concerned about them and are there if they need you.

"Try to talk to them openly, without judging them or rushing to tell them what to do - and if they don't want to talk, try contacting them through text or email."

Above all, make sure you get help if you need it - talk to friends, family, your GP, the school, or helplines such as those run by the NSPCC and YoungMinds.