YOU SAID:
She didn't know what she'd do
INTO JAPANESE
彼女は自分が何をするのか知りませんでした
BACK INTO ENGLISH
She didn't know what she would do
INTO JAPANESE
彼女は自分が何をするかわからなかった
BACK INTO ENGLISH
She didn't know what she would do
That didn't even make that much sense in English.