I would add some context on why this soliloquy is happening. It seems a little confusing to read it without ever learning why the sister is feeling the way she is. Is she at her brother's funeral? Is he dying? Is she dying? Are they both alive, but estranged and she's looking at a photo album and coming to a realization? The wording and the writing itself is pretty good, but the lack of context leaves it a bit unfinished to me.
You know what? You should shamelessly plagiarize other people. Take a story with a writing style you like, and COPY IT. I sucked at writing and I still do. But practice makes best. Taking other people's writing styles as references can be a good way to slowly improve.
I wanted to pretend I didn't read that and assume the sister grew up, matured, and told her brother this on her wedding because I would be in danger of drowning in tears otherwise. But, once you've read something, you can't un-read it... Why couldn't it have just been left to our imaginations... Great story though! Now if you would kindly excuse me while I drown (Ｔ▽Ｔ)
I think it's good enough on its own because my emo heart only wants to feel the pain with no closure.