I have two sisters and I've called them "sis (insert sister name)" since so young that when I was about 4 someone asked my sister's name and I said "sis Karol" as if sis was part of her name lol. Only one note, I said "mana" instead of sis, I translated it to sis here because it is pretty much the same meaning in all ways

Hello friend

Whaddup you sonofabitch?!

I pretty much always answer phone calls from my other (also adult) siblings by saying "Heya sister/brother"