Looking for reccomendations. I have read Ani to Imouto no Jijou, closing sister and rika.

They dont have to be blood related, just would prefer the brother being older or same age, prefer the older brother being more eager.

Since you already read Ani to Imouto no Jijou why not try Miwaku no Tobira from the same author?

hermespasser.github.io

I probably scouted for everything related to full-blooded incest. The other case I call them "stepshit"...
I noted that though I found cases of shill, day-to-day yuri incest manga or merely chapters with that kind of cool, relaxed athmosphere, I didn't found a manga with full-blood brother-sister (or mother-son, etc) that is both:
somewhat realistic (I mean what you would get by asking actual couples, which do exist IRL)
not smutty nor rapey
Exploring what it actually feels like to have both bounds together and magnified. With good sex scenes.

My reference would be: https://nhentai.net/g/291665/24/
But it's yuri.