YOU SAID:

My sister is being a jerk

INTO JAPANESE

私の妹はグッとしています

BACK INTO ENGLISH

My sister is terrified

INTO JAPANESE

私の妹はおびえています

BACK INTO ENGLISH

My sister is scared

INTO JAPANESE

姉が怖い

BACK INTO ENGLISH

I'm scared of my sister

INTO JAPANESE

妹が怖い

BACK INTO ENGLISH

I'm scared of my sister