Lots of really bad teachers out there teaching math without knowing the math themselves. The ED school requirements for math majors are laughable. I think one (if that) semester of calculus is all that is required. If math is her passion, then she should major in it; leave all the theoretical teaching, pedagogic nonsense and unproven theories to the ED schools.
There is a reason why Mathematics majors and Mathematics professors are frustrated at the decline of math competence in the US: ED schools.