Sisters
noun
Your older sister and your younger sister. These are your sisters.
しまい
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
あの二人って姉妹みたいだよね。
Those two are like sisters.
私は、三人姉妹の一人です。
I'm one of three sisters.
姉妹でゴルフのコンペに出ました。
The sisters participated in the golf tournament.