A.,
I too am there. Here is a great website that provides info on ADD for girls:http://www.addvance.com. It has lots of info and many links to others. Also, there are books out there that explain ADD in girls. Another good source is to check http://add.about.com and http://www.helpforadd.com/add-in-girls/ and http://www.4-adhd.com/girls-with-adhd.html.
What I have read in these sites is medicine, alone, is not the best treatment for children with ADHD. Medicine with behavior modification and diet are crucial for better outcomes according to the thousands of articles that I have read.
Now, we did take our daughter to a developmental pediatrician who did prescribe medicines. They did not work, made things worse. Please, have your friend take her daughter to see a pediatrician who is up-to-date on the meds. We have found so much more about the meds than what is out there. We were not aware that if a child has problems with agression, it will be worse if taking these meds. We had so badly hoped meds would work for her...it's painful to see her struggle academically and socially. We were disappointed to see that the meds that everyone else seems to have success with actually made our daughter worse. Our daughter does have sensory processing issues, and this learning disorder is often misdiagnosed as being ADHD. Occupation therapy has provided the most help with focusing and certain behavior issues. We are now going to try the behavior modification technique. We have changed the diet to eliminate red dye, high-fructose, refined sugar, and use Nordic Naturals Omega 3, and supplement her diet with vitamins like B-12, magnesium...nutrients that children with ADD seem to lack. Her grades, self-esteem is showing great improvements. I hope the behavior modification techniques that we have read about will help with the social aspects of a girl with ADD. It is so hard to see your child looked down upon because of her disability, not only by her peers but the educational system, as well.