In Ellen Raskin's The Westing Game, while it is true that Turtle Wexler figured out all four of Sam Westing's identities, won the game, and later inherited $200 million, in reality all characters in the book are winners. All characters are winners because Mr. Westing's purpose in creating the game was twofold: (1) find the best heir of the Westing fortune possible, the one who will think strategically and keep secrets--traits that are necessary for protecting the fortune; and (2) help the other characters find their own identities; in helping the characters explore and find who they are as people, he gets the opportunity to observe who they are as people.
At the beginning of the novel, the characters do not feel secure with their identities. For example, Turtle is lonely because she feels she doesn't have a real mother since she feels unloved by her mother, Grace Wexler, and Turtle's sister Angela feels she must marry Dr. Denton Deere though she doesn't want to. We learn more about the characters' unhappiness when they are asked to list their "positions" on the their receipts indicating they had received their letters inviting them to the first reading of the will. Grace shows her unhappiness when she, as the narrator describes, "wrote housewife, crossed it out, wrote decorator, crossed it out, and wrote heiress"; and Madame Hoo exhibits her unhappiness by just marking the receipt with an X to be filled out by her husband (Ch. 5).
But, by the end of the novel, all of this unhappiness has changed. Turtle feels she has found a surrogate mother in Flora Baumbach, whom she calls Baba; Angela breaks off her engagement with Dr. Deere; Madame Hoo and her husband became very financially successful due to the sales of Hoo's Little Foot-Eze; and Grace Wexler is the new happy owner of the Hoo's old restaurant, now renamed Hoo's on First, among many other happy endings. Most importantly, Turtle, the winning heiress, gained even more than just an inheritance.
Whereas once Turtle had hid her fears and anxieties behind her braid, by the very end of the story when Mr. Westing finally does truly die, she has gained a great deal of self-confidence and power. She is described by the narrator as having earned a "master's degree in business administration, an advanced degree in corporate law, [and] had served two years as legal counsel to the Westing Paper Products Corporation" (Ch. 30). We are further informed that she had "made one million dollars in the stock market, lost it all, then made five million more" (Ch. 30). In other words, she had blossomed into the type of heiress who truly could protect and even increase the Westing fortune.
Hence, while Turtle wins the game and the fortune, it can truly be said that all characters come out winners in the end--all what makes them truly happiest, what most matches their own identity.