The Quiet One—
Her family always called the "little adult." She could sit down and listen to anything and keep quiet, even from a young age. When she was six she sat down and listened to her father give a whole speech about the width of cauldrons and she remained completely silent the whole time.
She earned quite a reputation at school for being quiet, and she often found herself sitting there while people explained their problems to her and asked for advice. But if she ever had a problem, no one was there for her.
People are under the common misconception that quiet people don't have opinions. But she does, oh she does, and one day she's going to spill everything that's in her head and let everyone's secrets out.
How Teddy is only clumsy because he wants to be, how Vic is cruel to most people but hates herself for it, how Dom really cares about what other people say to her, how Louis GAY people—so stop asking him when he'll have a steady girlfriend! And one day she'll tell Jason Smith exactly how she feels and he won't come to her for girlfriend advice anymore.
One day she'll let all of the secrets out. But now Molly just doesn't feel like it. But people should watch out because one day she's going to blow. And she won't be "Quiet Little Molly-Wolly" anymore, she'll be loud and obnoxious and fun just like the rest of the family.
They'll just have to wait and see.