John Engler remembered that she "had been laid up at home for weeks, and the school made up study packs and stuff for her." Also, "She’d been just too sick with leukemia to go to school at all in the ninth grade, and she’d died halfway through the school year" LP10
Diane was included in the list of departed friends during the moment of silence at the 10-year Reunion.GM8
According to Wes she is not / was not related to Matt Caldwell, the main character in the book Blanche Tickle Girl.
He said that it was just sheer brain fade that I used that name twice.