Give a stream of consciousness and then the final answer. The film follows big band leader Glenn Miller (1904 -- 1944) (James Stewart) from his early days in the music business in 1929 through to his 1944 death when the airplane he was flying in was lost over the English Channel during World War II. Prominent placement in the film is given to Miller's courtship and marriage to Helen Burger (June Allyson), and various cameos by actual musicians who were colleagues of Miller.

Based on this passage, who plays glenn miller's wife in the glenn miller story?
The relevant information to answer the above question is: Prominent placement in the film is given to Miller's courtship and marriage to Helen Burger (June Allyson), and various cameos by actual musicians who were colleagues of Miller.
So, the final answer is June Allyson.