Watchtower goofs again.
There was no “principal of headship” before the fall. It was only after the fall that Eve was to suffer horribly in childbirth and that “your desire will be for your husband, but he will rule you”. Many translations explain it means Eve will desire to control her husband, but he will rule her.
In other words prior to the fall they had an equal, harmonious relationship. In fact I was reassured by older JWs as a kid that in paradise women would no longer be subject to headship and in heaven male and female no longer exist.