Sister: together for life?

When we were young you used to make fun of me
for watching such childish shows on T.V.
I tried to ignore you
But once you were gone I would scream because you said this to me.
I wanted to hang with you and I wanted to be your friend,
But in a quarrel or some tears it seemed it always would end.
Three years between us and you thought that was much too large
I would still try to fit into your clothes and be just like you in any possible way.
Once we reached a mature age our quarrels seemed to cease
Our differences accepted, our relationship mended, and our secrets slowly released.
I thought that we would be together forever and that you would never leave me
It is now I realize you will be gone very soon and it is now that you must free me.
You were my guardian, my role model, my best friend, and my sister.
You might not know how much you mean to me
I just wish we could start all over when we were young and you used to make fun of me.