YOU SAID:
She's bitten off more than she can chew
INTO JAPANESE
彼女は噛むことができる以上に噛まれています
BACK INTO ENGLISH
She is bitten more than she can bite
INTO JAPANESE
彼女は噛むよりも噛まれます
BACK INTO ENGLISH
She is bitter than bite
INTO JAPANESE
彼女は噛むより苦い
BACK INTO ENGLISH
She is bitter than bite
That didn't even make that much sense in English.