cousin的意思是表妹；同辈表亲（或堂亲）；堂兄（或弟、姊、妹）；表兄（或弟、姊、妹）；远房…。例如：She is my cousin.

sibling意思是兄弟姐妹；兄；弟；姐；妹。例如：The remaining 22%lived in the home of another family member (such as a grandparent, in_law or sibling), a non-relative, or in group quarters like college dormitories.