Quoted By:
Lets take a look at the actual Skyla look and highlight what we know to be a fact based on game evidence.
The only arguable one as you can see is the tank top, and they make long sleeve tank tops in reality, so it's not entirely far off, just slightly redesigned. Now interesting enough there are 4 variations of these particularly leaks.
Originally she was the Dragon Gym Leader, with an Ethnicity of "South American" and she was all about singing. The next iteration is basically identical to this one, only she's 5'10" and 26 years old, the next two iterations are pretty much exactly the same, all with an ethnicity of Hispanic. An interesting note is that they kept one of her hobbies being music, from the original iteration where she was the Dragon Gym Leader.
Now, with all that said, what can we extrapolate from 4 versions of the leaks, particularly this one. Chances of her height/weight being accurate are probably pretty accurate, but really impossible to actually tell. Her region isn't exactly cut off by impassable mountains, but Twist Mountain is to the north and it is a rather secluded forest town comparatively to the rest of Unova. Her dislikes being water and swimming never come up, the only info we have about that is she does like to swim at Caitlin's home. So we can scratch that one off.
So it stands to reason that there is possibility they scraped her being Hispanic, but considering how consistent the rest of the stuff is, especially between 4 different iterations and design changes over the course of Gen 5, it's probably safe to assume she is indeed Hispanic/South American.