Curate, connect, and discover
I imagine that Shen Yuan probably took care of his younger sister alot. Mostly because it's most likely that he was home the most and his parents + older brothers were most likely busy a lot.
Its to my belief that he was silently thanking his parents for that post transmigration because he knows more "feminine" things because of her (that are the norm in his new setting). I just imagine him braiding Luo Binghe's hair and remembering that he learned to braid because his sister liked to wear her hair in one. Shen Yuan picking out color coordinated outfits because his sister would always rant about it when she needed someone to take her shopping (she wasn't aloud on her own and sy was available). I also feel like he would be totally understandable if any of his female decibels asked to sit out because of cramps (unlike some male teachers)
Idk I just feel like SY would be close to his sister and that would give him a few advantages