I'm just going to throw similarly-aged women at the wall and see who sticks:Who does Edward marry now if Eleanor is not available?
I wonder if Margaret of Navarre or her sister Beatrice would work? Or maybe Constance of Aragon? Perhaps Margaret of Hungary too? (though significant butterflies would be required to make it work) There's also Elisabeth of Brabant, daughter of Henry II of Brabant (and OTL first wife of Albert I of Brunswick), though she might not be able to have children, which would require a remarriage at some point. Both Sophias of Denmark are the right age (the daughters of Eric IV and Abel, respectively) as well.
The issue I see is that many of the most politically-advantageous potential brides for Edward are all too closely related to him.