Yes, I too would worry about giving the wrong message... about trying hard things and perseverance. The decision to take the class is in the past and it is the current decision to persevere or opt out that must be dealt with IMO. The "changes for the better" that you mention hopefully include helping her learn coping skills for future situations that are similar. Clearly the work itself is not too hard given the great tests at the beginning. Can she take a 15 minute recess in the middle of the 1.5 hours? Run around at the park before class? Other parents of children with ADHD may have better suggestions. I'd approach this like any other unpopular task that must be done. Lots of different methods are used by parents on this site and some of my favorites include explaining the rationale for taking the class, the simple "this is the way it is" (which I suspect is similar to the dragging you mention) and bribery. Special snacks to take along or at pickup time for the ride home were quite popular when DD was that age. Money also works if your child is saving for something or just into money.
