I remember someone reporting that the real reason she left was grades, which would explain going back to the level she did. I also suspect the fact that she couldn't beat out Morgan factored in also.
To me, it was obvious that at the beginning of her freshman year, she was being groomed to be the next great point guard at Oklahoma. There was a video on SoonerSports.com of a skull session Coach had with DaShawn and Morgan. It seemed like Morgan's function was to assist DaShawn in shortening her learning curve. However, she was somewhat of a bust at that position. She had plenty of quickness and athletic ability, but she couldn't see the floor and run the offense effectively at all. She spent all her time going east and west rather than north and south. In the meantime, Morgan performed far above expectations.