A few things to check for: ask the school for the list of curricula they use. for e.g. what math do they use (if it is Saxon, Singapore etc, they will have the grade level on the book cover) - so you will know for sure if their math is 2 years ahead of PS kids. When I changed schools I asked for the exact books to be used for my child to determine if the acceleration promised was real or not.
Also try to get your DD to take an out of level achievement test through a talent search if you have not already done so. The scores should convince the school on the grade level acceleration.
And finally, let them know that you are looking for acceleration or skip and that would be the major factor in deciding to move from the current school. I am sure that they want your DD in their school and will try to accommodate you
