This elementary school teacher uses a simple lesson to answer her students' questions about why those in the class with disabilities get special treatment to help them overcome their disabilities in the classroom.
Then she (or the article editors) make the huge leap to why society must use "equity" to address social inequities such as in wages.
What she's calling "equity" is what society has always done, to some greater or lesser extent, to greater or lesser effect, with greater or lesser sensitivity, to people with disabilities. At some point in the distant past, someone who broke his leg got recuperative treatment instead of being put out of the camp.
I remember in basic training that guys who were overweight were also given special treatment...they were made to do more running. Guys who were having trouble following directions were given a lot more directions to follow...for more practice. Basic Training provided different treatment to trainees to obtain an immediate equal result: Everyone's graduation from Basic Training.
None of this equates to "There aren't as many women engineers in the company as male engineers, so we must higher every woman engineer that applies until the numbers are equal."