Since you felt the need to draw attention to it...
I don't typically check nico sources because I don't have an account there, and without looking at tags to support one or the other, this virgin killer Johnston could very well be confused for a more casual Atlanta. However, now that I confirmed I can see tags on nico without an account, I know for certain it is Johnston.
The outfit and twin tails can certainly make it seem like it's Atlanta. Yet, her demeanor is not like hers and plus the ribbon in the hair is a dead giveaway that it's Johnston.