At least in my state, students who are identified as needing services must be evaluated every three years (by law) to determine continuing eligibility. The goal is to get them the services they need to perform in the least restrictive environment. It does not mean she'll even end up receiving services or that she will always need them. Some students just need a bit to get over that hump till the age maturity evens out.
Testing should help determine if it is ADD or just immaturity. It is best to know now so that good habits can be set. Many teens I know get into bad habits with their ADD (such as using it as a licence to do nothing) or feel more stigma if they are identified later.
At any time in the process you should be able to call a meeting to re-evaluate. Just write down all your questions and make sure you get satisfactory answers and stay involved in every step of the process.