As an aging mother, Amanda realizes that she needs to have her children in stable positions so that they may be able to provide for her. Her conflicts with Tom indicate that she does not trust him to provide for her--she has also seen his application to the Merchant Marine. In addition, she may worry that he may follow the path of escape that her husband, whose smiling portrait lurks over the family.
With the play's setting in the 1930s, Amanda certainly is aware of the limited opportunities for young woman. This is why she has encouraged Amanda to enroll in Rubicam's Business College. Then, when she discovers that Laura has dropped out of the school, Amanda sees a "gentleman caller" as the last savior for Laura. This savior image is suggested by Tennessee Williams's production notes that the news from Tom that a man is coming is referred to as the "Annunciation" and the candles are Laura's "altar."
If Laura marries, Laura will be provided for, and Amanda gains some comfort from knowing that she has two people who can care for her in her old age. Therefore, to Amanda, Laura's marriage is a solution to the family's problems.
Amanda is convinced that unless Laura marries, she will have no one to support her after Amanda dies. She put Laura in business school but Laura so sick to her stomach during a typing test, that she "threw up on the floor." After that, she only pretended to go to school until her mother accidentally found out she didn't go back after being sick. After that, all Laura does is sit all day and play with her glass collection and play the "worn out records" that her father left when he deserted the family. Since Laura is a failure at business school, her only option according to the times, is to find a husband who can support her. But, since she never leaves the apartment, it is doubtful she will ever find a husband on her own. Thus, Amanda is obsessed with finding a young man to bring to the apartment to meet Laura and, hopefully, fall in love with her. Amanda has seen the letter Tom received from the Merchant Marines and knows Tom wants to leave the family so her obsession is made even more severe because she knows Tom will not be there to support his sister, either.
Amanda wants Laura to actually start her own life so she is trying her hardest to find her a suitor. She knows Laura has no life and knows it is almost impossible for her to interact with a man so she is trying to do everything possible.
Amanda is obssessed with finding a suitor for Laura. She believes that Laura needs a man to be happy in life. She does not have any skill, which is proof in her business course. Laura has not has any gentleman callers. Amanda fears that Laura will end up alone and sad, so she needs to marry. She needs suitors, so Laura can marry, and be happy.