YOU SAID:

I've just launched a dog at my sister

INTO JAPANESE

私はちょうど私の妹に犬を発射しました

BACK INTO ENGLISH

i just fired my sister the dog

INTO JAPANESE

妹の犬をクビにしたところ

BACK INTO ENGLISH

Just fired my sister's dog

INTO JAPANESE

妹の犬を解雇したところ

BACK INTO ENGLISH

Just fired my sister's dog