I told her that I know about these things and the letter itself is far more important than those checkboxes and adcoms don't really pay close attention unless she put me below 50% or something like that.
Your basis for this assertion?
Check boxes. Who would've figured that it would make a LOR writer all anxious. (And, yes, she is a tenured faculty member but hasn't had a whole lot of experience being involved in grad admissions)
Please stop publicly denigrating this person who is doing you a favor (and certainly knows more about graduate admissions than you do). - DvF