My daughter is sitting her 11+ exam, at the end of November & is already very nervous, any advice?

She's been working hard, and now she said she doesn't want to do it as she's too nervous. She is a very bright little girl, and she will hopefully be trying to get into two grammar school, the first exam is November 29th, unfortunately no one else in my family is as clever as she was, and none of us have taken exams into the grammar schools, so any advice to settler her nerves? We keep telling her that as long as she tries her best that's fine but she's creating more fuss then necessary