Final answer:
The governess in the story might have known what Peter Quint looked like based on information she received from others.
Step-by-step explanation:
The governess in the story may have known what Peter Quint looks like based on information she received from others, even though she did not see his ghost herself. Although it is stated that the governess has been dead for twenty years when the story is being told, the events she experienced when she was young could have been shared with others before her death. Additionally, the governess might have gathered information about Peter Quint's appearance through conversations with other characters or through descriptions in letters or other written accounts.