In Mary Shelley's Frankenstein, after Victor creates the monster and becomes ill, Elizabeth (his adopted cousin and sweetheart) writes to him.
In Elizabeth's letter she first asks after his health, telling him that he should not even attempt to write because of her concern for his fragile health. Elizabeth also comments on how much his brother Ernest has grown, that Victor's father's health is strong, and that even the youngest of them, William, is growing tall, laughing and handsome. (There is a great deal of foreshadowing in this letter, a good bit is this section.)
Elizabeth then draws Victor's attention to Justine Moritz, who had been brought into the Frankenstein home through a gesture of charity on the part of Victor's mother. Justine had been less a servant and more a companion to the children. Elizabeth shares how Justine had, with sadness at her necessary departure, returned home to care for her invalid mother who had been very unkind to her as a child. It was a difficult time for all: for Justine in caring for her difficult mother, and the Frankenstein household for missing Justine, as one would miss a member of the family. When Justine's mother passes, Justine returns again to Geneva, and there Elizabeth has welcomed and cared for her. (There is a great deal of foreshadowing here, as well.)
Elizabeth describes Geneva, and even shares some town "gossip." In closing, she now begs one penned line from Victor to know that he is well, sending along her deep appreciation to Clerval for his care of Victor during his serious illness.
Victor does indeed write back to her, and this moment seems to signal a significant improvement in his recuperation.
On Chapter 6 of the novel Frankenstein, Elizabeth writes a long letter to Victor in which she mainly states the anxiety that the family feels upon not having heard from Victor in a while. She also begs Victor to confirm in his own writing that he is, in fact, getting better from his illness.
Victor’s illness had everything to do with the excessive amount of time that he had been spending in his study. The strain that this placed on him affected both his daily life as well as his health. Henry was able to suggest some distraction for Victor, and he hesitantly took it. Yet, this conduct was completely unlike him and he did not realize that he was beginning to worry his own family.
In the letter Elizabeth also told him the story of Justine Moritz, who was rescued from a negligent home and put as a servant in the Frankenstein household. Elizabeth related to Victor for the first time the origins of Justine, and explained the circumstances in which she entered the household. Apparently Victor, who really liked Justine, did not know this part of her story.
Finally, Elizabeth conveyed information about William and assured Victor that things were alright. This, she did as a way to cheer up Victor and to entice him to write back. The end of the letter was a plea for him to write her “even one line,” so that she can rest assured that Victor is doing well.