Final answer:
Jane is surprised by Mrs. Fairfax's warmth and friendliness, which was unlike what Jane expected for a governess's reception.
Step-by-step explanation:
Jane is surprised by the friendliness of the encounter with Mrs. Fairfax. Upon her arrival at Thornfield, Jane expected a more formal and distant reception typical of that given to governesses. Instead, she finds a warm welcome where Mrs. Fairfax offers to help her with her shawl and bonnet, suggests getting her something warm to drink, and treats her like a visitor rather than a subordinate. Jane notes this treatment, acknowledging that it's not what she anticipated and cautiously reminds herself not to get too excited too soon, indicating a mix of surprise and a degree of skepticism given the social norms of the time.