Over a third of girls as young as eleven say that comparing their lives to others is one of the greatest worries they have about spending time online.
And girls are also concerned that while their parents are well aware of threats to their safety and online grooming, less than half (47 per cent) of those questioned feel that their parents realise the pressures they face on social media.
This comes as more and more girls and young women turn to social media including Snapchat, Instagram and Youtube as recreational hobbies, engaging with both their friends and with celebrities.
The older girls get, the more of an issue it becomes, with 40 per cent of girls aged 17 – 21 citing it as their second greatest worry, after being distracted from their academic work.
A third of girls also say that they worry about how they look in photos, and a quarter say they worry that they feel the need to check their phones first thing in the morning and last thing at night.
The gap in perception of online dangers shows that parents are at risk of underestimating the impact that a life online can have on their daughters.
Katie, 17, a Girl Guides Young Leader, said: “Social media can be an amazing tool for young people to make their voices heard, but as these figures show, it can also take a toll on girls’ self-esteem. It’s sad to see how many girls and young women today are feeling mounting pressure online - whether they’re comparing themselves to peers or worrying about their appearance.
“Comparing yourself to others can be an easy trap for girls and young women to fall into, especially given how often we use social media to keep up with the lives of friends and celebrities. That’s why Girlguiding’s ‘Free Being Me’ body confidence workshops are so important to help girls speak up about the pressure they feel and find positive ways of dealing with it.”