I can't say what she's from, but this is fan art of a character that a Korean artist has been working on on livestream. I imagine she's from a gacha game, maybe one that's not out yet.

The artist is tagged as Hyulla on here, but here's his Pixiv just in case: https://www.pixiv.net/en/users/3842786

I can't even remember when I saw him drawing this character, a good few months ago. Maybe the beginning of the year.