Personally, I think the name "Miss Sister" is actually limited by age, so it should be used according to different actual situations. I often hear people call me little sister on many occasions. Actually, I'm not very exclusive on most occasions. I think it's a polite and more kind address. Generally speaking, I go to barbershops, restaurants, supermarkets and so on. Many people will call me little sister out of courtesy, but I have found a rule that people who call me little sister are usually people my age.
In one case, I really don't like being called my little sister. For example, on formal occasions, I prefer to be addressed as a lady. First, because of the occasion, I shouldn't use too colloquial words to express myself in formal occasions. Second, communicating with me in the tone of a little sister will give people a feeling of disrespect. There is another situation. I don't like people calling me little sister. I don't like him calling me that in front of a boy I hate. I think this kind of address has a playful tone in it, which will make me feel uncomfortable. I believe many girls have similar views with me. Most girls actually don't hate boys calling her little sister, so you boys can judge flexibly according to the actual situation.
To be on the safe side, when boys don't know how to address girls correctly, I think it's respect. Teacher Jia? In fact, this is the most respectful and safest name. Now with the development of society, we have some new changes in dealing with people and things. No matter what happens to us, the most important thing is not to lose our manners.