The pictograph of a woman crossing her legs means woman. In the image you can see her with a fabric or towel hanging over her left arm.
HSK-Level: HSK 1
HSK Word: 女儿 (nǚ'ér) - daughter
Frequency: 224 out of 9933
Popular words with 女:
女人 (nǚrén) - woman
美女 (měinǚ) - beautyful woman
女装 (nǚzhuāng) - womens clothes
The pictograph 女 (nǚ) for "woman" in one character combined with 未 (wèi) for "missing", you get a woman that is missing something for being a finished woman - she is the "younger sister". But if you really want to say "younger sister" you got to use this Character twice: 妹 (mèimei).
HSK-Level: HSK 2
HSK Word: 妹妹 (mèimei) - younger sister
Frequency: 1185 out of 9933
Popular words with 妹:
妹妹 (mèimei) - younger sister
小妹 (xiǎo mèi) - little girl/sister
学妹 (xuémèi) - younger female schoolmate