Responses
https://www.mangago.zone/read-manga/the_strongest_characters_in_the_world_are_obsessed_with_me_bored_corona_kids_version/ Maybe this one? They both have silver hair and the ML did hate his sister but i can’t remember anything about academics or what not. LMK if it’s right ( ̄∇ ̄")
Hmm maybe it’s this one? There is a flashback from brothers pov in chapter 26 that is similar to what you are describing ヾ(☆▽☆)
https://www.mangago.zone/read-manga/the_villain_s_match_is_too_perfect/
I only see clips about it and I'm sure I added this to my list.
I think the FL is transmigrator(?) She has an older brother which excels in academic (?) but the young FL also is good and excels more him that he kinda hated his sister. Then later something change and FL no longer approach her brother. I think they both hair lighter color hair, it's silver.
I really forgot if it's even right, but can someone tell me what you think?