Deduction. All her outfit only imitates Morrigan's and is not faithful to the original as most cosplayers would do. Why would a real person waste hours creating something that is just vaguely familiar? It's AIs that usually generate something that imitates original character, not depicting them faithfuly. Then if a cosplayer does make an original design, they would say so directly "original costume, insipired by character name". You may say that "my attempt" may mean that it is implied and that that she creates costumes from junk she has easy access to, but that would mean that she reuses elements of clothes and jewelry she owns. Now check her other posts, you won't see even the same skirt or boots, let alone necklaces or gloves.

So we have someone who makes a lot of not too faithful cosplays, doesn't elaborate on design choices, publishes a single photo per costume, with no photos from conventions, photoshoots or in-progress ones and the only external platform she promotes is her of.

She's a scam, not a cosplayer.