Theme is the central message or insight that is revealed through a story. Anyone can find the theme just by analyzing the characters' actions and the consequences of their actions. For example, If a character's actions help him or her reach her goals, then that action may be viewed more positively by the reader. In the short story "Rules of the Game" by Amy Tan, Lindo Jong works very hard to impart daily lessons that will ]help her success to her daughter. The actions she used to encourage her daughter is to try to succeed by mastering the art of "invisible strength". Finally based on the characters' actions and the results of their consequences, I believe that the theme is that true strength is calm, patient, and strategic.
If you are referring to a girl getting pregnant or a couple having sex than in some cases a unexpected pregnacy can thrust the pressure of marriage upon minors. But way less today than in the past.