It's true, we are made in God's image and likeness.  But that doesn't mean that the resemblance is physical or even psychological.  God has no body and God has no gender.  Rather, we resemble God because both we and God have free will, the element which allows us to love.  If we can accept that God is the author of infinite variation, then we can see our transgendered siblings as intrinsically ordered children of God.