I am flying to Orlando in August via AirTran Airlines, with my 17 and 12 year old daughters. They have a different last name then me. I know the 17 year old can bring her drivers license., what should I bring for my 12 year old? She doesn't have a school id, The airline told me a birth certificate, but with our names being different I'm not sure that would work?? Any ideas, maybe get her a photo id, but not sure where to get one?