Theres no definite criteria on who is “unauthentic trans person or not.” So therefore any trans person is subjected to being labeled as “unauthentic.” Even if there was, unauthentic is an adjective. She still is fearing trans people, this meeting the definition of transphobic.

Making guesses and assumptions about me doesn’t help your argument. It’s another adhomenim. I’m not here to defend my character, this argument isn’t about me. It’s about if JKR meets the criteria of being transphobic. She’s afraid of trans people, you can call them inauthentic of authentic all you want, she’s still afraid of them, and this is transphobic.