So i'm a fairly new player and i just learned that Shiroko is widely considered as a wolf. But i really don't get it, so i did research... and still couldn't find any actual proofs.

Here are what i found instead:
Shiroko's theme is Midsummer Cat.
The theme first played for her in main story chapter 1 and her L2D, plus there is no student with the same L2D
theme and fits the name... except New year Serika.
She acts more like a cat.
In her regular L2D, when she was nervous(Sensei "interrogate" her in an empty classroom), her ears flatten slightly FORWARD. For wolf's case, their ears flatten BACKWARD the two sides of their head.
Now let's take a look at her riding L2D. Her ears twitch very slightly when she was happy. Cats do that when they are happy/pleased (That's also a sign of angry cat but it's clear she was happy during that time). Also, Serika does the same thing in her new year L2D. Coincidence much?
"Her name is translated to Sand Wolf"
So, is Hibiki a "Hill Cat"? That's the meaning of her name. I feel like Shiroko's name is only there to serve her lore as Anubis. I mean, i doubt Hoshino is a Falcon(Horus), or Nonomi is a Hawk(Nephtys).
"Her ears are wolf ears"
She literally has the same ears as Serika. Their maker is Hwasang, the main artist of Elsword, a very old game that i played. As far as i can remember, he has always been drawing cat ears like that. You can check his art on his website, search Hwangsan Elsword artist.

TL;DR: Other than name, nothing shows Shiroko as a wolf. And it's not enough because there are atleast 3 characters whose name/lore doesn't define their race. Shiroko's behavior and theme doesn't seem to fit wolf either.

That's all for now, thanks for reading. I did this for fun and i don't mind if Shiroko is actually a wolf after all. But eh, i just don't see why.