I haven't used her, but based on her website she does psychoeducational testing. That will confirm ADHD.
It is less expensive than a neuropsychological examination but if that's your primary or only concern it should be fine.
Given that your daughter is a teenager, I assume you know based on her school performance that other learning issues (dyslexia, dyscalculia, dysgraphia) are not a concern and thus a shorter test batter won't miss areas of concern.