Throughout the first season of "Friday Night Lights," it is assumed that most of the main teenage characters (Jason Street, Tim Riggins, Lyla Garrity, Tyra Collette) are seniors. Specifically Tyra, who has an entire subplot with guidance counselor Tami Taylor devoted to turning her grades around in her last semester so she can apply for colleges and get out of Dillon, Texas. Then...Tyra's on the show for two more years and this subplot is more or less repeated in season 3, which is her actual senior year.
As a sophomore, why was Tyra acting like she only had one more semester left to change her GPA? I personally chalk this up to the writing staff not expecting to get more than one season of the show and then de-aging them after season 1, but I would like to know if there's ever been a clear, concrete explanation given for this that is in-canon.