Does she have other opportunities to perform or is it just the big recital?
DS's Suzuki teacher insists on multiple opportunities to play, for family, for friends, in front of his fellow students etc. These are all informal, and the groups are very forgiving of mistakes. The goal is to keep performance so much a part of natural life that it never becomes a big deal. He does have big recitals now, but because he is desensitized to performing he really doesn't suffer from perfectionism or anxiety.
I think if you have only a few big recitals, and no other performance opportunities, that puts the pressure on and increases the anxiety.
