You get what you get and you don't throw a fit.
By the time you're in 8th grade, I find it hard to believe that your daughter didn't have an idea of how she was doing in the class. She's had more than ample time to be proactive and ask for ways to bump her grade up. Instead, she's now taking the initiative with only 2 days left in the grading period. If I was her teacher, I wouldn't appreciate it one bit. It's one thing to ask for extra assignments when there's time for the teacher to prepare and properly grade them. It's quite another to panic two days before grades are out and then expect the teacher to jump. Sounds like this is the perfect time for your daughter to learn a lesson. Sorry.