YOU SAID:

My family is having a barbecue outside.

INTO JAPANESE

私の家族は外バーベキューしています。

BACK INTO ENGLISH

My family was outside is barbecue.

INTO JAPANESE

外にいた私の家族はバーベキュー。

BACK INTO ENGLISH

I was outside the family's barbecue.

INTO JAPANESE

家族のバーベキューの外だった

BACK INTO ENGLISH

It was outside of the family barbecue

INTO JAPANESE

家族のバーベキューの外だった

BACK INTO ENGLISH

It was outside of the family barbecue