I would be cautious about guiding your daughter into too narrow a path at this point, since she is so young. Writing can be applied to many areas of study and work. Creativity can also apply to many areas of study and work.
By all means find a middle school writing program if she wants one. But as the other poster implied, keep it relaxed, and don’t lock her into the identity of “writer” at this age.
She has many middle and high school years ahead still to develop as a writer or in any other interests she may have over those years. Making something she enjoys doing into a “thing” and adding pressure to talent can have negative consequences for many kids.
She does not need to choose a high school based on this interest and talent. I know kids from mediocre public high schools who won national writing awards. Try to choose a high school experience that is a good fit for her emotionally as well as academically. Many kids who experience early academic or professional pressure, end up burning out.