What is fascinating about Rachel’s place in the show is that she is a fixture. She is the Glee club, but functionally speaking she is not a part of it. She is hovering somewhere above it, acting as a leader and a soloist, but is never really “one of the gang.” So the idea for Rachel is not necessarily to have her accept her inner loser with pride, but rather to ground her amongst the other characters as a functional member of the Glee group.
This is outlined in the very first episode. Rachel was almost immediately constructed as an isolated character. Consider her original solo: “On My Own.” In one way, the song speaks to Rachel’s lovesick nature, yes; but on the whole it’s a testament to the idea that Rachel is isolated within the narrative, in almost every way. And not only that, but Rachel’s conversation with Will in the bleachers establishes that she doesn’t want to be isolated. It’s this scene that identifies where Rachel Berry’s character arc needs to go. “Being a part of something special makes you special,” she tells Will, and whether or not that’s true, it’s clear that Rachel Berry wholly believes that. And even though she’s been in Glee Club since Day One, Rachel Berry is not truly a part of Glee.
– Rachel Berry and the Spotlight: Rachel, the Glee Club, and Belonging