In this paragraph, the word forbiding means the same as ominous. Ominous simply means that something that's threatening or bad.
From the passage, we are informed that a "dark and forbidding wood of giant arborescent ferns rose". This gives us the impression that there's something threatening there and that's an ominous sign.
The paragraph is a narrative inferences which it has she in ir and its gonna be "The narrator is showing the feelings and thoughts"because the author is trying to persuade you to give you the enjoyment and how the person is struggling through a poor performance.
