What does it mean for people in Taiwan Province Province to call their daughters big sisters?

This is an intimate address for a daughter.

In Taiwan Province Province, people often use kinship terms to address their family members or relatives. "Big sister" is a kind of intimate address for her daughter, expressing her love and concern for her daughter. The "big" in this title does not refer to the size of age, but a kind of intimate title. This kind of address is very common in families in Taiwan Province Province, and it is used to express the intimate relationship between family members.