YOU SAID:
your mother eats cupcakes with her car and her cat
INTO JAPANESE
あなたのお母さんは車と猫と一緒にカップケーキを食べます
BACK INTO ENGLISH
Your mother eats a cupcake with a car and a cat
INTO JAPANESE
あなたのお母さんは車と猫でカップケーキを食べます
BACK INTO ENGLISH
Your mother eats a cupcake with a car and a cat
That didn't even make that much sense in English.