Just see the secretary at the school, take her birth cert in case and say that when you went the other day you noticed that her name was misspelt and wanted to make sure it was correct on her forms. She is the best person to nip this in the bud as she is the one who does the main paperwork for new enrollments. It also wont hurt to see the teacher and let her know how to say her name as sometimes when you don't know how to say a name you will get it wrong until enlightened.