Oh boy ... don't get me started! I work in this world of models and photo shoots. Here's my very strong opinion:
Modeling schools are usually mostly a way for people to make a lot of money from "wannabe's" who don't have the look and could never be a model anyway.
If a girl (or a guy) has the right stats and right look, they can walk into a fashion or commercial modeling agency and get signed on the spot. The agency does not care if they have any training or not. The first thing they will do is arrange to have the new model "test" ... which means start working with one or more professional photograhers to get images for her new portfolio ... which in turn will get her work. It's pretty simple .. and most models learn as they test (which they are encouraged to do often with agency approved photographers). Sometimes the model will pay the photographer, makeup/hair artist and some times a fashion stylist, but more often than not, if she's gorgeous, most photographers and their team will do it free and give her prints to use in her portfolio.
About the only thing a model might need to learn is to walk the runway ... but most models don't ever make it to the runway, anyway ... unless they are really tall and skinny. Her agent might arrange a few classes like that ... but never in a "modeling school". Makeup, hair and styling are all done for her on most paid shoots, so she doesn't even need to know that ... unless she's a promotional model, which is really just a pretty girl handing things out at conventions and things like that. In that case, she has to prep herself for the gig. But most pretty girls already know how to put on makeup, fix their hair and find a sexy dress.
So no ... modeling school is not only unecessary, it's a waste of money! A new model must spend a lot of money on her portfolio and comp cards so her agency can market her ... she doesn't need to be spending it here.
The only time I would recommend a modeling school to a young lady is if she's feeling awkward about girly things, wants to learn how to look prettier and needs to learn some poise and confidence. But that's not the girl that can model, anyway. Modern modeling schools are the equivalent of the old fashioned "charm school".