One possible theme could be loss. Losing a loved one, a job, or a home can be a nightmare for anyone.
Another theme might be isolation. Maybe she was in a situation where she felt all alone, for example, if she moved to a new place and didn't have any support system there, and then some bad things started to happen to her, making it a nightmare. Also, financial stress can be a theme. If the family was in debt or she suddenly lost her source of income, it could create a real nightmare situation for her as a wife who has to manage the household.
Another theme might be disillusionment. Maybe the story is about someone who had a certain view of America, perhaps the American Dream, and then had that view shattered by the reality they experienced, thus leading to an 'American nightmare'. And a third possible theme could be survival. If the story is about a difficult situation, then the main character had to find ways to endure and make it through the tough times.
One possible theme could be trauma. Since it's based on a true story, it might explore how a real - life event caused long - lasting emotional and psychological damage, like a nightmare that won't go away.
I'm not sure specifically which 'anybody's nightmare true story' you are referring to. There could be many stories that might be considered someone's nightmare in real life, like a story of a person losing their home in a natural disaster or facing a serious illness without proper support.
Financial distress can also be a theme. If a mother is struggling to make ends meet and can't provide the basic necessities for her children, like food, shelter, and education. She would be in a constant state of worry and stress, which is like living in a nightmare. The mother feels helpless and desperate as she wants the best for her children but is unable to fulfill those needs due to financial constraints.
Another theme might be loss. This could be the loss of a loved one, like a child or a parent, and how she has to deal with the aftermath while still maintaining her role as a wife. It could also be the loss of her own identity within the marriage, if she has sacrificed too much for her family and feels lost as an individual.
One possible theme could be fear. As it's a nightmare, fear would likely be a central aspect, whether it's fear of the unknown, fear of a person, or fear of a situation.
One possible theme could be the loss of innocence during Christmas. Something that was once pure and joyous like Christmas becomes a source of fear.
The 'wife's nightmare true story' could also be about relationship issues. If there have been arguments or a lack of communication in the marriage, her nightmare might be her subconscious fear of the relationship falling apart. Maybe she dreams of her husband leaving her, which could be a sign that she's worried about the state of their marriage and wants to address the problems.
One possible theme could be the subversion of expectations. Christmas is often associated with joy and celebration, but the 'nightmare' in the title suggests that this story will turn those expectations on their head. Another theme might be the idea of color as a symbol. Since 'pink' is in the title, it could represent something that is initially seen as positive but then becomes a source of trouble.