Re-Tracing, I am sorry you have gone through that. The brain naturally blocks out memories that we can't handle at a given time, and "releases" information as we mature. You may never have a full running "movie" of what happened, but that does not mean that it didn't. It is easy for you to waver between denial and recognition and that's ok. Don't feel guilty about blaming or not blaming your brother. Often times, especially when the abuse happens at a young age, we develop "trauma bonds" with our abusers. This is natural. You may never get to a point of blaming him, and I (personally) don't think that it is absolutely necessary, but you will have to work through the abuse to see how it has impacted your life (consciously and unconsciously). Are you seeing a therapist?

Also, in terms of your brother, at such a young age, I don't think he put what he was doing and "abuse" together. I could be wrong, but I don't think he probably thought, "I am going to sexually abuse my sister now." He may have been starting to go through puberty and having no idea what to do with all of the thoughts and sensations. Don't get me wrong, this in NO WAY justifies what he did. I say all that because 1. he may not even remember it, 2. if he does, he may not ever admit to it/apologize/etc. Also, if he is "very against sexual assault" to use your words, there may be, somewhere subconsciously, a part of him that feels guilty.

I have no idea if that makes sense or if that is helpful at all. :/ Keep posting, you are very brave. I would also encourage therapy if you are not already going. It may sounds scary, but it is an excellent way to work through something like this with someone that "knows the ropes." Best of luck, keep us posted. (hugs)