There is only the one solution which will actually work. Our problem, if we wish to view it as such, is that men and women have different propensities – note propensities, not certainties – for desiring to care for their own young children. It is only changing that which will eliminate the gender pay gap:
Think through this again. Assume even that I’m right, the gender pay gap is a consequence of, and only a result of, a generally and on average difference between men and women in the desire to care for young children. More women would like to do this than men. From that, all else flows. So, when do we think this preference is going to end? For it’s at that exact same time that the gender pay gap is. My own estimation is that the preference never will change, which is a bit of a problem for any attempt to close that gender pay gap, isn’t it? Sure, maybe I’m just a patriarchal cisgendered heteronormative doing some mansplaining. Or maybe human beings just are a sexually dimorphic species.
That is, much as it will annoy, the only solution.