女 means 'woman':

It is probably a picture of a woman sitting cross-legged.

姐 Jiě is 'older sister':

妹 Mèi is 'younger sister':

Common words: 姐姐 jiějie 'older sister', 小姐 xiǎojie (actually pronounced xiáojie) 'Miss', 妹妹mèimei 'younger sister', 姐妹 jiěmèi 'sisters'