YOU SAID:

She shared a cigarette with me while her brother played the guitar

INTO JAPANESE

彼女は弟がギターを弾いている間にタバコを私と共有しました

BACK INTO ENGLISH

She shared cigarettes with me while my younger brother was playing the guitar

INTO JAPANESE

私の弟がギターを弾いている間、彼女は私とタバコを共有しました

BACK INTO ENGLISH

While my brother was playing the guitar, she shared a cigarette with me

INTO JAPANESE

私の弟がギターを弾いている間、彼女は私とタバコを共有しました

BACK INTO ENGLISH

While my brother was playing the guitar, she shared a cigarette with me