Congratulations on your daughter getting into Dana Hall. It’s a really good school. I would wait until the first 2 months after school begins before you decide whether your daughter should transfer to the other schools. Whether your daughter transfers depends on how she does in her new school.
Some more information: Dana Hall School is one of the top all-girls schools high schools in Massachusetts. It has high SAT/ACT scores, low student-teacher ratio. The school receives good reviews from students and parents, and matriculation to many ivy colleges.