Sacrifice
Mildred sacrifices everything she has for Veda. In this way, she stands in for all parents everywhere, in that her unconditional love sometimes leads her to make excuses for her daughter even when she ought not to. When we first meet Mildred, she is a woman who is happiest in the kitchen, providing for her family. She bakes pies and has an entrepreneurial spirit that is all in service of giving her daughters the best that money can buy.
As the film progresses, however, Mildred's sacrifices become larger and more outlandish. As Veda becomes more and more demanding, spoiled rotten by her mother's gifts, Mildred chooses to continue to provide for her daughter rather than cutting her off. This is pushed to the limit when, even after learning that Veda is having an affair with her husband, and even after Veda kills him, Mildred is willing to do whatever she can to get Veda out of harm's way. Right up until the moment when Veda is arrested for Monte's murder, Mildred is intent on sacrificing and covering up for her daughter's mistakes. Thus, sacrifice, particularly maternal sacrifice, is a major theme in the film.
Hard Work
The only person who really excels in the movie is Mildred, and it is based on the fact that she works so hard to make a living. After being left by her husband, Mildred takes her fate into her own hands, getting a job at a waitress, and quickly making her way up the ladder, until she owns not only a successful restaurant, but an entire chain of restaurants throughout California. Mildred's hard work turns her into an exceptional businesswoman and helps pull her out of destitution.
The only problem is, the harder Mildred works, the more her loafing hangers-on—Veda and Monte—want to take from her. Unlike Mildred, Veda believes that she deserves the best without ever having to work for it. Similarly, Monte, who inherited all of his wealth and then squandered it supporting an extravagant lifestyle, doesn't understand the value of money, and so uses up Mildred's, manipulating her into providing for him without ever lifting a finger himself.
The irony is, of course, that even though Mildred's hard work is what supports Monte and Veda's decadent lifestyles, they still look down on her for having to have a job.
Gender Roles
Mildred and Ida are the only two characters who seem to work hard in the film, in spite of being women during the Great Depression, a time in which being a woman with a job was uncommon. The film subverts prevalent notions of gender to depict the story of a woman who takes matters into her own hands and makes a life for herself when the men around her will not. After Bert leaves her, Veda encourages her mother to marry Wally, so that they can have a good life, but Mildred is more interested in working hard than in marrying someone she can never love. With professional opportunities available to her, Mildred does not want to have to be an unhappy housewife in exchange for security; she wants to create her own security. In this way, Mildred Pierce is a distinctly modern woman, who knows how to navigate the world of men and create her own happiness without being a dependent.
Ungrateful Daughter
Veda is a horrible brat, a femme fatale, and a cold-blooded villain. While she is the reason that Mildred makes so many sacrifices and works so hard to provide for her family, Veda ultimately proves to be the least grateful daughter in film history, a decidedly bad seed who is happy to have her love bought, but never feels any genuine affection for her mother. Their relationship is a kind of Freudian case study; while Veda is the narcissistic extension of everything Mildred wanted—refinement, taste, luxury—Veda only wants to differentiate and exploit her mother, and ultimately, take her place. Bert warns Mildred in the first scene that Veda is a brat who will never love her in the way that Mildred so desires, but this does little to deter Mildred from seeking that affection. Veda only disrespects her mother more, the more Mildred dotes on her.
Exploitative Men
When Mildred becomes single, she finds herself not only financially troubled, but also romantically vulnerable, with no man to protect her from the lascivious men in her life. No sooner has Bert left her than Wally rings her doorbell, inviting himself in, asking for a drink, and pursuing Mildred with a dogged sense of entitlement, as though the more he persists, the more likely she will be to fall in love with him. Mildred must contend with his wolfishness with poise, and use him when she needs him.
Then, while Monte is considerably more appealing and charming, Mildred must also fend him off for a time before she agrees to an afternoon swim. He is just as persistent in his approach, and seems not to be able to take no for an answer. Thus, we see that Mildred must not only contend with being alone in the world, but also with the predatory minds of the men with whom she is associated.
Murder
The film starts with a murder, and in true noir style, follows the story leading up to the crime, so that a detective is able to solve it. While much of Mildred's flashback contains more domestic details, mundane everyday problems that constitute a drama rather than a crime thriller, the viewer knows that all of the events are leading up to Monte's death. Thus, the theme of murder hangs over every event. In the beginning, it seems as though Mildred is the one who committed the murder, and as we see her relationship develop with Monte, it seems more and more clear that she will be driven to kill him. However, the twist ending subverts our expectations, and shows us that the murder was far more complicated, a crime of passion, than we had been led to believe.
Old money vs. new money
Part of what makes Veda so difficult to satisfy is the fact that wealth and finery is not all she is after. Rather, she wants to have the kind of wealth and privilege that Monte Beragon has: an older, more established wealth that is about history as much as it is about money. Part of why Veda looks down on her mother is the fact that Mildred has to work for what she has, rather than inheriting it from wealthy relatives. When Mildred confronts Veda about conning the Forresters out of money, Veda says, cruelly, "You think just because you made a little money you can get a new hairdo and some expensive clothes and turn yourself into a lady. But you can't, because you'll never be anything but a common frump whose father lived over a grocery store and whose mother took in washing." In this quote, we see that Veda cares just as much about where someone comes from as how wealthy they are, and she looks down at her mother as a commoner.
