Reili
Honestly, it's a bit of a let-down seeing Shiro mastering all those abilities so easily. It feels more like a sudden power up. Well, considering how much experience she has, something in whatever tier she currently is shouldn't be too much of a challenge. Though I would love to see her try really hard to obtain something as it feels more gratifying that way
Well, once again, here before MilkGod, so one more cat fact: The proteins humans are allergic to aren't actually part of the fur, they're in the saliva that gets onto the fur. That's why hairless cats still can cause a reaction. Now, if you want a cat that doesn't cause one, you can look for a Siberian, as the breed has a higher chance of producing cats with low levels of the proteins commonly reacted to by those with cat allergies. You'd still need to get the kittens tested, which is kinda expensive on top of the breeder's prices, but...
How is she going to explain her ability to control any human's water and ice? I was thinking a new Frozen Hell skill: Glacial Reversal. Start with her ice-fire, melting away about her opponent's mana "signature" from his skill, maybe absorb it/convert it into hers. The more of her own mana used in proportion to her opponent's, the faster the conversion, the faster the skill (mirrored to her enemy), the deadlier it is!