Does Jin Xiaoyu have any brothers or sisters?

Yes

Jin Xiaoyu has a brother named Hyo-cheon Kim. Besides, there are other cousins.

Jin Xiaoyu, male, 1972 was born in Tianjin. He is a translator and a member of Zhejiang Translation Association. Jin Xiaoyu was unfortunately disabled as a child. After dropping out of high school, he was diagnosed as "bipolar disorder", with manic and depressive episodes alternating.