Was K.C. abused in some way by her mom? Is that why she and Jax seem to fit so well together? She comes off as being very lonely, sad, lost and misunderstood. Like he's the strong one and she's the silent one.
From what you've read, I think it can be inferred that K.C. keeps up appearances. She holds almost no control over her own life, and she's stuck in unhealthy relationships. This book takes place two years after high school graduation, and K.C. finds herself in still the same situations, but whereas she had Tate before, now she feels as if there's very little to hold onto. Tate has her own life now, and K.C. starts to have time to reflect and consider what's happening to her life. And in comes Jaxon Trent... :)