In Book One, chapter 15, Calvin addresses what it means to say that man is made in God's image. He helpfully notes that when Paul says that man, and not woman, is the image of God (1 Cor. 11:7) “it is evident, from the context, that it merely refers to the civil order.”
I find this distinction helpful for three reasons.
First, for making clear that all people share in God's image equally.
Second, that Calvin has a model for interpreting Scripture in context.
Third, that Calvin distinguishes between the order of creation as such and the civil order.
Elsewhere (and throughout) Calvin argues that the civil order is shaped by the Fall, but retains the image of the good order of creation. I think it reasonable to believe that as we form and reform the civil order, we can move some ways from the unequal relation of the sexes in the civil order that Calvin knew, to a more equal order that is closer to the creation ideal.