I don't understand your question. Are you saying that "The forest closed upon her like a pair of jaws" is evidence that the forest is on private land? If that is your question, then I don't know what gives you that idea. The fact that a forest is private land can't be shown by the use of similes or metaphors etc - you would have to call it a "private forest" if it was really important to know that it's private.
Student or Learner