Swatthatfly & ZD – I think you misunderstood JA’s question. It’s not about the difference b/w boys’ and girls’ schools.
It’s about the difference in the way that schools are chosen for each. With girls it generally goes by family. The general rule usually is that you have to go wherever your older sisters went, and you are not necessarily given a choice. By boys, you are not expected to go where your older brothers went.
Each time a boy in a particular family gets to Eighth grade, it is a given that choosing a Yeshiva for him is a new decision. With the girls in the family, the decision is made once – when the oldest girl is in Eighth grade, she and/or her family and the high school decide where she and all her younger sisters are going to go.
I have a friend who has 10 girls, ba”h. When her oldest daughter applied to high school, the school knew that when they decided to accept her, they were deciding to accept all 10 girls, and when she chose a school, she knew she was choosing for her entire family.