We are accustomed to calling those who are good-looking "little sister". Remember in English: don't say "little sister", proper Chinglish. It can be called cute girl, little princess, belle/beauty, sweet heart.
Sister can be an older sister or a younger sister. But adding little restricts the translation of sister to younger sister. Therefore, in English, little sister can only mean little sister. In our spoken language, we affectionately call you little brother or little sister. It’s not because the other person is older than us, that’s why we shout like this. It's just that the other person is good-looking, which is a kind of compliment! You understand when you see this! The translation seems correct, but it actually has nothing to do with it.
The English name for little sister is: little princess
Little princess, a very cute and affectionate name. You can sell melons like the queen and boast about yourself! It can also be used to compliment your girlfriend.
Example: Would you like that, my little princess? Do you like it, my little princess?
The second English name for young lady: cute girl
Cute girl. Praising a girl for being cute is undoubtedly the safest thing!
Example: At first, I just wanna have a date with her, but then I found out she was such a pretty girl. What he means is: At first, I just wanted to have a date with her. Look, but then I realized she was a really cute girl.
The third English name for young lady: belle/beauty
Belle can be used as a person's name, or it can also mean "beauty"
Example: Dude, I met a belle today. I just can't take my mind off her. Man, I met a beautiful young lady today. I still can't forget her.