YOU SAID:

I am going to the theater with my girlfriend and my mother

INTO JAPANESE

私は彼女と私の母親と一緒に劇場に行きます。

BACK INTO ENGLISH

I go to the theater with her and my mother.

INTO JAPANESE

私は彼女と私の母親と一緒に劇場に行きます。

BACK INTO ENGLISH

I go to the theater with her and my mother.