We have to remember that our account of Mary Morstan comes from Watson, who is in love with her.

He describes her as a sweet and refined young woman, saying of her when he first meets her at Holmes's office:

She was a blonde young lady, small, dainty, well gloved, and dressed in the most perfect taste.

Although she does not have much money, she is entirely a lady in her refinement. In many ways, with her trembling dependency, dignity, and courage to come forward to seek her rights, but only to the extent of looking for help from men like Holmes and Watson, she is an ideal Victorian angel of the home.

This fair damsel in distress with her big blue eyes, blond hair, and English ways is also a perfect foil to the sinister "Oriental" characters out to thwart and cheat her. We learn that her self-control is "perfect" and that she is "resolute." When she discovers her father is dead, she turns white and seems about to faint, as a good Victorian woman would, but she rallies and composes herself after Watson brings her water. Later, however, she weeps from stress. She is both courageous and yet dependent on males like Watson to protect her.

At the end, she is delighted to accept the good-hearted Watson's proposal of marriage, showing she conforms to Victorian social norms. Watson makes the proposal after thanking God that she has lost her treasure. Otherwise, he would have looked like a fortune hunter. They have the following exchange:

" . . . I can tell you how I love you. That is why I said, 'Thank God [you lost the treasure].'"

"Then I say, 'Thank God,' too," she whispered, as I drew her to my side.

Watson, as the normal narrator of the various accounts of his friend's endeavours, gives an accurate account of all characters that are presented to the reader, even if they lack the perspicacity that Sherlock Holmes is able to bring to the narrative. The introduction of Mary Morstan in Chapter Two of this novel is no exception. Note the following information the reader is presented about her character:

Her face had neither regularity of feature nor beauty of complexion, but her expression was sweet and amiable, and her large blue eyes were singularly spiritual and sympathetic. In an experience of women which extends over many nations and three separate continents, I have never looked upon a face which gave a clearer promise of a refined and sensitive nature. I could not but observe that as she took the seat which Sherlock Holmes placed for her, her lip trembled, her hand quivered, and she showed every sign of intense inward agitation.

Even though she is described as being "limited in means" through her rather plain and simple clothing, the admiration of Watson for her is clear through his identification of her as being unique amongst women and speaks of her "refined and sensitive nature." In addition, note the way that it is her vulnerability and fear that also seems to form part of the attraction that Watson instantly feels towards her. Mary Morstan is presented as a woman in need of men to help protect and guide her, and this is something that Watson seems to find appealing. The introduction to Mary Morstan therefore foreshadows the romantic attachment that will develop between them.