YOU SAID:

she must have been out of her head

INTO JAPANESE

彼女は頭から離れていたに違いない

BACK INTO ENGLISH

She must have been out of her mind.

INTO JAPANESE

彼女は気が狂っていたに違いない。

BACK INTO ENGLISH

She must have gone mad.

INTO JAPANESE

彼女は狂ったに違いない。

BACK INTO ENGLISH

She must be crazy.

INTO JAPANESE

彼女は狂っているに違いない。

BACK INTO ENGLISH

She must be crazy.