How very unprofessional of her to say anything like that, under any circumstance.
If even the Principal is noticing a bit of a backwards trend, you have reason to investigate it further.
On the math, our son has done similar things. I think he became so used to doing everything fast in math and that was almost his claim to fame. It's taken some time and is still a work in progress to get him to slow down on math. I'm guessing the reading reluctance/comprehension concerns are something different than the math impulsivity. But that's just a guess.
