Explain what Amanda proposes to Tom concerning his future and lauras

Amanda is worried that Tom will abandon them. Fearful for Laura's future, Amanda tells Tom that he can leave if he can find a replacement - a gentleman caller for Laura, who will eventually marry her and provide for her. Amanda exhorts Tom to overcome selfishness. An increasingly frustrated Tom tries to break off the conversation and go to work, but not before he begrudgingly agrees to look for a gentleman caller for his sister.