>>42702825>Tengu is from folklore, fairy is from folklore. I'm going to give you the benefit of the doubt, you didn't just imply every creature from "general" Folklore is a fairy. Otherwise it doesn't matter how many examples are there, that fact is besides mechanical reasons they exist. It's safe to assume, since there's nothing implying otherwise that Florges would also exist as well - and that's a pure fairy type.
Anything else, is 100% pure fan-theory speculation. ALSO, if Gamefreak actually had balanced their game, Ice-types should be faster and have more resistances. Lets take Fairy out of the equation for a moment, A strong Fast Ice-type would sweep through her team easily. Three of her Pokemon are weak to Ice, including her ace Garchomp. Infernape destroys Lucario and you can easily take care of Milotic. Basically It's more of a mechanical/balance reason as she was so "difficult" to beat. Throw Fairies in there and she's even easier to beat.