1. She will have fewer distractions.
The social static and inherent distractions which occur when you mix adolescent boys and girls together in a coeducational school just do not happen in a girls' school. The social expectations and stereotypes can be broken down. There will be time enough later for the distractions which members of the opposite sex provide. Fewer distractions mean a girl can focus on being herself, finding out who she is, exploring new worlds, lines of thinking and so much more. She can think outside the box with relative impunity. And that is a good thing.
2. She will benefit from teachers who are trained to teach girls.
Teachers in a girls' school are hired because they believe in this kind of education. They understand how girls learn. They provide the kind of nurturing and encouragement a girl needs in order to become all that she can and wants to be. They provide and cite role models which appeal to and encourage girls.
3. She will benefit from a focussed educational and community environment.
When a school does not have to accommodate both sexes, it simplifies the running and organization of the school. The only focus is girls and their needs and activities. No more mixed messages and signals being sent on the playing field or in the student lounge.
4. Her career aspirations will no longer be limited or discouraged.
Women in politics are still somewhat of a novelty in this country. Women at the top of the corporate ladder are few and far between. Women in academia have enjoyed somewhat more success than some of the other professions. We could go on and on citing examples of pursuits and professions where women have made inroads. Imagine how much different our world would be if the percentages of women at the top of all these endeavors were greater? The logical and analytical skills which women bring to the table would be a refreshing counter to all those years of stubborn, egomaniacal males who have done a less than stellar job of running just about everything.
Girls need to be told and made to believe that they can run things. They can be university presidents and, for that matter, President of the United States. Girls schools do that. Her career aspirations will no longer be limited or discouraged in a girls' school setting.
5. "When girls go to single-sex schools, they stop being the audience and become the players." - Robin Robertson
This is the bottomline and one of the most compelling reasons why girls benefit from a single sex school setting. Why would you want your daughter to sit back and be passive? Far better to give her the courage and the experience in high school to face the challenges ahead with equanimity and aplomb. This is the 'can do' generation. Give her the education which will allow her leadership and other strengths to blossom.