In most cases, Hetty Fether is considered fictional. Stories like this are often crafted by the imagination of the author to entertain and engage readers rather than being based on real events.
It's hard to say. Maybe if there's enough interest from fans and a good business case, they could come back. But there are no definite indications for now.
Definitely. Aunt Hetty on Matrimony is indeed a short story. It typically has a limited number of characters and a focused storyline centered around matrimony.
I'm not sure who Trevor Holt specifically is in this story without more context. It could be a fictional character created for a particular book, movie, or other form of media.
Perhaps a fanfic where Hetty's sister is an old acquaintance of one of the NCIS LA agents. She shows up with a mystery from their past that they all have to solve together. This could lead to flashbacks and revelations about the agent's early days, and how Hetty's sister was a part of it all.
Well, it depends on how you define 'good'. Trevor Story has shown flashes of brilliance, but his consistency can be a bit up and down. However, when he's on his game, he can be a real force to be reckoned with.