I am reading A woman makes a plan: advice for a lifetime of adventure, beauty, and success by Maye Musk, but I've never seen the use of 'teach' in 'teaching this modeling school' in this context:
“Here was this beautiful woman,” she will say, “who is teaching this modeling school. Great model, dresses terribly. Just terribly.”
I learned from here that the correct one should be 'teach at a school'. Is the collocation 'teaching a school' idiomatic? If not, why is 'teach a class' correct?