“I feel like they should help you bring up your grade because you’re sooo close. A friend of mine had trouble with a teacher who offered no extra credit (she was in a similar situation as yours). She eventually talked with the guidance counselor/school dean.”
Actually, in a quarter grade an 89 is not so close to a 90 - in one of my classes it could be 10-20 points. Also, what do you mean “trouble” because there wasn’t extra credit, and why would the GC or dean do anything except explain to the student that she should have done the work that was actually graded for regular credit?
“Just ask! The worse she can say is “No”.”
Again, this is not the case, OP’s reputation will suffer for being the kind of kid who would do this.