YOU SAID:

my mom is my father's wife, but also my sister's mom, and she is my grandmother's daughter, my aunt's sister, my cousin's aunt and my child's grandmother

INTO JAPANESE

私の母は私の父の妻ですが、私の妹のお母さんでもあり、彼女は私の祖母の娘、叔母の妹、私のいとこの叔母と私の子供の祖母です

BACK INTO ENGLISH

My mother is my father's wife, but also my sister's mom and she is my grandmother's daughter, my aunt's sister, my cousin's aunt and my child's grandmother

INTO JAPANESE

私の母は私の父の妻ですが、私の妹のお母さんでもあり、彼女は私の祖母の娘、叔母の妹、私のいとこの叔母と私の子供の祖母です

BACK INTO ENGLISH

My mother is my father's wife, but also my sister's mom and she is my grandmother's daughter, my aunt's sister, my cousin's aunt and my child's grandmother