YOU SAID:

My mother works for her boss, that is also my uncle

INTO JAPANESE

私の母は上司の下で働いています、それは私の叔父でもあります

BACK INTO ENGLISH

my mother works for a boss, who is also my uncle

INTO JAPANESE

私の母は上司の下で働いていますが、その上司は私の叔父でもあります

BACK INTO ENGLISH

My mother works for a boss who is also my uncle.

INTO JAPANESE

私の母は私の叔父でもある上司の下で働いています。

BACK INTO ENGLISH

My mother works for a boss who is also my uncle.