Example sentences
wǒ我jiě姐jie姐shì是hù护shì士。
My older sister is a nurse.
jiě姐jie姐bǐ比wǒ我dà大liǎng两suì岁。
My sister is two years older than me.
About this word
姐 is "older sister", said twice. The repetition is how Chinese marks sibling words, and the second syllable goes neutral, so it sounds like JIE-jie rather than two equal beats. Outside the family, 姐 is the normal polite word for a woman a little older than you, which is why shop assistants get called 小姐姐 and a colleague may be 张姐. English "sister" lets you skip the question of age, but Chinese will not: 姐姐 and 妹妹 are different words, and the same split runs through 哥哥 and 弟弟.
The story behind the character
姐
姐 is 女 (woman) with 且 on the right giving the sound. Xu Shen's entry is a small surprise: 姐，蜀謂母曰姐. In Shu, roughly modern Sichuan, this word meant mother. So 姐 started out as somebody's mom and drifted one generation down to older sister.