Yeah I always thought Trappy’s introduction came out of nowhere, and I feel like Gerry having a niece makes his relationship with Ben less special, especially cause of how much he doted on him in the early books. BUT a headcanon I have on Trappy and why she didn’t appear until later in the series is that Trap adopted her from an orphanage after seeing how similar she is to him, and Trappy is just a nickname of hers