YOU SAID:
She ate ate what's eating her
INTO JAPANESE
彼女は彼女を食べているものを食べた
BACK INTO ENGLISH
she ate what was eating her
INTO JAPANESE
彼女は食べていたものを食べた
BACK INTO ENGLISH
she ate what she was eating
INTO JAPANESE
彼女は食べていたものを食べた
BACK INTO ENGLISH
she ate what she was eating
That didn't even make that much sense in English.