Board Thread:Speculation House/@comment-4830106-20140808001942/@comment-24994749-20140813131747

Just saying, but it was never stated that before Beacon Ruby didn't have any friends outside of Yang. It is clear the sisters are close and all but Ruby didn't seem uncomfortable with the idea of Yang moving on to Beacon and she having to remain at Signal two more years on her own. Also, during the night before the Initiation, we see her writing to "the gang back at Signal" and she says it's "weird not to know anyone".

Ruby clinging to teaming up with Yang could steam from a ton of reasons, difficulty at making new friends is only one of them, she has all the odds against socialization at Beacon: she is 2 years younger than everyone else and while at other stages of life a 2 years gap it's nothing, among teenagers it can mean they are going through two entirely different maturity states; she got moved up those two years out of the blue by the headmaster himself, when you think that other people have trained all their lives just to apply for a chance to take the initiation exam, it is reasonable to worry about what others might think of you; she is rather introverted. So, yeah, between being in a team of strangers and a team with her sister, the sister idea sounds better.