I am also lucky to have a sibling, an older sister, who took great care of me when we were children.

sibling 是由古英语 sibb（亲属）和 -ling（表示"属于...的人"）组成的复合词，字面意思是"同血缘的人"。在现代英语中专指"兄弟姐妹"，不区分性别，包括兄弟和姐妹。