YOU SAID:
I was transformed into a girl.
INTO JAPANESE
私は女の子に変身しました。
BACK INTO ENGLISH
I was into girls.
INTO JAPANESE
私は女の子に。
BACK INTO ENGLISH
I was a girl.
INTO JAPANESE
私は女の子だった。
BACK INTO ENGLISH
I was a girl.
That didn't even make that much sense in English.