Then lots of baby mages will not have the resources to go elemental-befriending. 

The blue mage has six elemental friends already and wants to collect the whole set!

That seems inefficient. Are the baby mage's parents aware that there is only one mage teacher and if she is slowed down catching up students without such advantages their baby mage will get a worse education? Perhaps the elemental friends could be shared.

The baby blue mage's parents will pay Maurabel extra to teach their daughter at her own pace instead of sticking her in a crowded classroom full of purples. Lots extra.

Maurabel is not in it for the money.

It seems unfair to the capable students to teach the class at the pace of the slowest students. Maybe there could be two classes.

"Your daughter might not even be good at magic."

She might not! It's not really a blue occupation. If she's the worst in the class it'd be unfair for all the more capable students to be stuck waiting, right?

"I'm probably going to split it up just because of sheer numbers but I won't know who's good at it until there's been more assessment."

Has she considered that caste might be fairly predictive.

"Intelligence has to do with some of it but isn't well-correlated with number of affinities or magic talent per se."

What goes into magic talent?

"It's its own thing. I've heard it compared to cooking and tapestry design and remembering your dreams and dancing."

...it's probably green. That would make the most sense.

A lot of its uses among humans are kinda purple or orange.

Maybe spell development is green and spell stuff is purple or orange.

Anyway she'd appreciate if they'd let some other little mages come play with their daughter and her elemental friends.

Anybody who would like to fly their children and their children's staff out to this country estate in Cene is welcome.

She finds a few dozen elementals and they help her find more and eventually all the kids have at least one.

Statisticians think maybe it is something in freshwater clams. The population of the southern hemisphere, where spring is approaching, promptly starts eating tons of freshwater clams. Several governments pass laws that only pregnant people can buy freshwater clams. Charities spring up to help pregnant poor people afford freshwater clams. Everyone everywhere prohibits reds from possessing, ordering or eating any freshwater clams.

If the reds in her rainforest want them Maurabel is not going to ask them not to ask Waters to bring them some.

An amendment to international treaties about reds is added obliging everyone to take steps to reduce the risk of red mages, including denying them clams and killing them if you learn about them. There is some vague interest in action against the rainforest rogue reds but nothing concrete yet.

Well, does the international community want the only trained mage on the planet to be working on a school, or do they want her trying to defend her rainforest?

They want to be safe from red mages teleporting all around touching things.

Mages. Cannot. Teleport. Only elementals can do that and they can take non-mage passengers too if they want.

Yeah and they're scared of that too!!