Wise-beyond-her-years, Shannon is Pat and Eileen’s youngest and brightest child. Though she’s a clever, resourceful fourteen-year-old, her moral compass could definitely use some re-calibrating. One of Shannon’s big secrets is that she’s been using the money she raised for poor children in Africa to actually buy herself a car even though she’s not quite old enough to drive. Shannon, who is always eager for a “lusty debate,” seeks answers to her toughest religious questions from her priest as she prepares for her upcoming confirmation, leaving him in a bit of a spiritual crisis himself. Though she may never get the explanations she’s looking for, one thing is clear: Shannon’s going places in this world. But whether that place is a federal prison or the White House remains to be seen.
In the episode The Real Man, Shannon had gotten herself a job at the mall, selling pretzels at the fictional mall restaurant, "Tilly Ramsay". She kept her mother oblivious to this because she knew that she wouldn't approve of it. She loved having this job though, because not only did this kind of responsibility give her the maturity and education for being an adult, but this was also the first legal and ethical thing she did in order to earn money.
In addition to Shannon's greed, she had come out with another big secret in the episode The Real Man. Shannon had admitted that she had no faith in God or any belief in his existence. Being the smartest and most observational member of the family, Shannon had questioned her faith and come to the conclusion that there was no God. When Eileen heard about this, she had Father Phil answer her questions and convince her to believe in him again, which he was not successful at. At this time, Shannon had a job at Tilly Ramsay's and after Eileen had figured out about it, she convinced her that worshipping God was like working at Tilly's. Shannon had never met Tilly before, yet she still believes that if she works for the restaurant, she will get a paycheck for it. This convinced Shannon that although she doesn't believe in God, she should still go to church and do the things he wants her to do. In the episode The Real Confirmation, she said that back when she believed in God, she pictured him as a female, thinking that it was better to relate to a God of the same gender as she was.
Shannon is the youngest and smartest child in the O'Neals family. Although she's generally a nice and respectful person, the way she uses her intelligence isn't entirely ethical. She makes sure she obeys the rules, but finds loopholes in the rules in order to do something that the set rules are attempting to prevent. She does things such as running a black market, manipulating the priest into donating money to her, and buying all of the tickets to the school dance and selling them to the students for a higher price. Her motive for doing these things is all driven by greed. Shannon's main goal as of now is to earn enough money buy a car, despite the fact that she's not old enough.