He may write to update her on family matters, such as news about the kids if they have any. He could also write to plan future events, like suggesting a dinner date at their favorite restaurant or a weekend getaway. He might use the letter to offer words of comfort and support if she's going through a tough time, or simply to make her smile with a funny anecdote from his day.
It could be about his love for her. Simple as that.
One scenario could be that your father is away on a business trip. He writes to your mother to tell her about the new places he has seen, the people he has met, and how much he wishes she was there with him.
I'm not sure of the specific story about your father writing to your mother. It could be a love story where your father expresses his deep affection through letters. Maybe he writes about his day, his dreams, and how much he misses her when they are apart.
I don't know the specific story about your father writing to your mother. It could be a love letter full of his deep affection for her, perhaps reminiscing about their past memories together, like their first date or a special trip they took.
The significance could be that it shows the influence a father has on a person's life narrative. It might explore how a father's actions, values, and words shape the story of his child's life.
One possible theme could be family influence. Since the father writes the story, it's clear that the family has a strong impact on an individual's narrative.
One possible theme could be family. Since it's the father writing his story, family relationships are likely to be a big part of it.
Maybe the father turns out to have been misled in the past life and his actions were not as malicious as they seemed.
One possible theme could be family dysfunction. Since the mother is described as a monster, it indicates that there are problems within the family structure. Another theme might be the struggle for independence. If the mother is overbearing like a monster, the characters in the story may be fighting to break free from her control.
Perhaps the plot could be that the father has a secret that he only wants to face in the dark. So he sits there every night, thinking about it.