Helen Stoner is shown to be protective of her stepfather in spite of the fact that he is a brutal man with a bad reputation in the neighborhood and sometimes mistreats her. In "The Adventure of the Speckled Band," Sherlock Holmes finds specific evidence of abuse.

“You have done wisely,” said my friend. “But have you told me all?”

“Yes, all.”

“Miss Roylott, you have not. You are screening your stepfather.”

“Why, what do you mean?”

For answer Holmes pushed back the frill of black lace which fringed the hand that lay upon our visitor's knee. Five little livid spots, the marks of four fingers and a thumb, were printed upon the white wrist.

“You have been cruelly used,” said Holmes.

Evidently Helen does not suspect her stepfather Dr. Roylott of planning to kill her or of having killed her sister Julia two years earlier. If she had not consulted Sherlock Holmes she probably would have remained at Stoke Moran. Her sister was killed by the poisonous snake after having heard the strange whistling sound for several nights in a row. Helen relates that her sister indicated this to her shortly before the night she died.

“ ‘Because during the last few nights I have always, about three in the morning, heard a low, clear whistle. I am a light sleeper, and it has awakened me. I cannot tell where it came from—perhaps from the next room, perhaps from the lawn. I thought that I would just ask you whether you had heard it.’

Apparently it took Dr. Roylott about four tries to kill Julia with his poisonous snake. If Helen had not consulted Sherlock Holmes and had continued to occupy the bedroom next to her half-insane stepfather, she probably would have been dead within a comparable amount of time. If she had consulted someone else, that other person was highly unlikely to be as helpful as Holmes. That other person probably would not have dared to come to Stoke Moran to inspect the bedrooms and probably would not have arrived at Holmes' conclusions anyway. Throughout the story, even including in the title, the word "snake" is never used except at the very end, when Roylott is found dead. The word "snake" would have given the whole plot away. So it is always referred to as the "speckled band."

Helen would have gone on sleeping under the ventilator, and every night her stepfather would have sent the snake through the ventilator and down the dummy bell-rope to the sleeping girl's bed. It was only a matter of time before Helen would have been bitten. Naturally there would have been a big inquiry, especially since Helen would have died with the same symptoms as her sister Julia. But in the end Dr. Roylott would have succeeded in killing both his stepdaughters without being identified as the perpetrator, and he would have been free to enjoy the entire proceeds of his dead wife''s estate.

The author stresses Helen's protectiveness of her stepfather in many ways. She even bailed him out of jail when he was arrested for throwing the blacksmith off the bridge. Conan Doyle wishes to explain why Helen didn't just move out of Stoke Moran. She has an aunt, Miss Honoria Westphail, who lives near Harrow, who would surely take her in. And she is engaged to be married very soon. Her fiance should be willing to place her in a safe hideaway and arrange for them to be married almost immediately. Conan Doyle wants to emphasize that Helen does not suspect her stepfather, partly in order to show the reader that without Sherlock Holmes' immediate involvement, Helen would surely die. Time is of the essence. Holmes is consulted at around seven o'clock in the morning at Baker Street, and before seven o'clock the next morning Dr. Roylott is dead and the case is all wrapped up. Holmes has not only saved Helen's life but has simultaneously solved the "locked room murder mystery" involving the death of Helen's sister Julia two years before.

Even after Roylott's death, Helen had gotten Watson to promise not to publish an account of the case because she was still trying to protect the family name. Watson explains at the beginning of the story:

The events in question occurred in the early days of my association with Holmes, when we were sharing rooms as bachelors in Baker Street. It is possible that I might have placed them upon record before, but a promise of secrecy was made at the time, from which I have only been freed during the last month by the untimely death of the lady to whom the pledge was given.

What do you think would have happened had Helen not consulted Holmes?

Helen Stoner did not have much money of her own. Her stepfather controlled her assets and probably only gave her a small allowance. She had very little freedom, like most unmarried women in Victorian times. She could not have gone to the police for help because no crime had been committed, except of course for the murder of Julia Stoner two years before, which was a closed case. Helen could not go to another private detective because there probably were no private detectives in those days, and anyway she couldn't afford to pay them. Sherlock Holmes is compassionate enough to help a person like Helen without asking for a fee. He is also intrigued by this so-called "Locked-room mystery." If Helen hadn't heard of him, her plight would have been dire. The author, Arthur Conan Doyle, takes pains to show how she knew about Holmes and also knew he would help people in distress in some cases.

I have no one to turn to—none, save only one, who cares for me, and he, poor fellow, can be of little aid. I have heard of you, Mr. Holmes; I have heard of you from Mrs. Farintosh, whom you helped in the hour of her sore need. It was from her that I had your address. Oh, sir, do you not think that you could help me, too, and at least throw a little light through the dense darkness which surrounds me? At present it is out of my power to reward you for your services, but in a month or six weeks I shall be married, with the control of my own income, and then at least you shall not find me ungrateful.”

Helen is engaged to a Percy Armitage, but she does not feel that he can be of much help to her. He has no experience as a detective, and he obviously could not come and spend a night or two in her bedroom. Therefore the chances are that she would die in the same horrible manner as her sister. Dr. Roylott cannot afford to give her the money she would inherit upon her marriage. He would do his utmost to have her killed by his snake. She might continue to hear the whistle, but she would have no idea that an Indian swamp adder was slithering through the ventilator, down the dummy bell-rope, and onto her bed every night. The snake comes from a hot, humid climate. It would not try to escape from the house, especially since the author has emphasized that the weather is unusually cold. Instead, the snake would be likely to crawl right under the covers and curl up beside the sleeping Helen. It probably wouldn't bite her unless she turned over in her sleep and was lying right on top of it. But this was inevitable. Sherlock Holmes saved her life. Otherwise she would have been dead within a short time.

Dr. Grimesby Roylott would undoubtedly come under suspicion, since both his stepdaughters would have died the same way. But he would have disposed of the snake after it was no longer of further use to him, and it would have been difficult for Scotland Yard to make much of a case against him. That explains why he is so concerned when he finds that Helen has come to London to consult Sherlock Holmes and why he tries to scare Holmes away from Stoke Moran. Holmes, as Roylott knows, could be a lot more dangerous than any Scotland Yard detective.