Facebook has become one of the biggest influences on the lives of girls, according to a survey.
A study of eight to 15-year-olds for National Family Week found 40% of girls identified Facebook as one of the most important things in their lives - compared with 6% of boys.
Parents were found to underestimate the significance of technology.
The role of social networking was particularly important in families with a single mother as parent.
The survey, carried out last month and based on 3,000 parents and 1,000 children across the UK, looked at the perceptions of children and parents of family life.
It was commissioned by National Family Week - an event supported by charities including the NSPCC and the Women's Institute - which encourages families to spend more time together.
The survey presents a picture of girls using social networking as something central to their social and family life.
Girls saw websites such as Facebook as much more influential than television, magazines, celebrities and even their own brothers and sisters.
Asked to name the three most important things in their lives, the most popular choices for girls were friends, family and then Facebook and MSN.
For boys, family was much more of a popular choice - chosen by 73% of boys, compared with 53% of girls. For their other choices, boys identified money and friends as their next most important things.
Social networking was a much lower priority for boys - only 6% selecting it in their top three things in their lives, compared with 40% of girls.
Girls are also more likely to believe that technology - in the form of social networking and mobile phones - has a major influence on their lives.
While 41% of girls think technology is one of their biggest influences, only 17% of boys believe this.
Relationship with parents
Girls see their big influences as parents, teachers and technology - while boys identify parents, friends and school.
The survey claims that parents have failed to keep up with their children's use of technology, overestimating their own importance in their children's lives.
According to Facebook's own policy, children should not register to use the website until they are aged 13.
The survey also looked at how children viewed their relationships with their parents.
It found that both boys and girls would much rather have stories read to them by their mother - but that girls felt closer to their fathers, while boys felt closer to their mothers.
National Family Week runs from 31 May to 6 June.