I also read a study about a year ago that proved that sensory integration strategies were just as effective for ADHD kids as for SPD kids. That made me wonder. Also, the less compatible the school environment is with her level of giftedness, the more "ADHD" she is going to *seem*.
Spend 1 day with my DD and you will be convinced that ADHD is a real disorder and that there is no way sensory integration strategies would help in any significant way. Everyone can tell immediately if she is medicated or not. Her focus is 0-1 out of 10 unmedicated and 8-9 medicated. You can tell almost exactly when the medication kicks in and wears off. If sensory issues were causing all of her focus issues, that would not happen. A lot of people don't see SPD as a distinct disorder. The American Academy of Pediatrics recommends it not be diagnosed at all, unless it is in conjunction with certain disorders like autism, ADHD, developmental coordination disorder, etc.