CAMom, no, not all kids are like that and yes, she should be evaluated for ADHD. My dd also did well on those standardized tests because she is smart - and they are multiple-choice, so she could immediately "guess" the correct answer. The questions don't require sustained attention. I hope your friend finds the answers she is looking for, because it can be a challenge.
Thank you for taking the time to post about the situation/process with your friend. It is very similar to the process we have gone through with our daughter and shed light on just how much her ADHD may have affected her testing.
- Sky