There is 4 years between my sister and me too, me being the youngest and yes, I don't think I ever saw her as being my age or someone to confide in - always she was a figure of authority, she was prefect at school then head girl at both schools - someone who ratted me out constantly. But even so she was also never in the "adult" category either, which parents and aunties were. It's a difficult relationship, but one where I was never a child to her but an annoying little brat! :))

In our family photos, you can tell exactly when my oldest sister stopped being a kid and assumed responsibility. Her total aspect changed. It's kind of heartbreaking, really.