The first meaning is "little sister, little brother", which is a general term for "girls and boys" and is used to greet ordinary people. Because "small" means promising, it is called "demon sister and brother (little sister and brother)", which means praising beauty, which is equivalent to "beauty and handsome boy" now.

The second meaning refers to the youngest sister and the youngest brother. Used to say hello between brothers and sisters. Similar to this meaning are "Aunt Yao, Dad Yao" and so on.