YOU SAID:

Hey sister just went to the bar for a martini

INTO JAPANESE

ちょっと姉はマティーニのためにバーに行きました

BACK INTO ENGLISH

A little older sister went to a bar for Martini

INTO JAPANESE

姉がマティーニのバーに行きました

BACK INTO ENGLISH

My sister went to a bar in Martini

INTO JAPANESE

私の妹はマティーニのバーに行きました

BACK INTO ENGLISH

My sister went to a bar in Martini