Blushweaver would not be willing to leave the Court of the Gods, and it would be difficult to leave it, as Returned need Breath. While Stormlight can stand in, the Returned in Hallandren do not know that. Elhokar, as politically inept as he is, would not be able to politically navigate the Court of the Gods.
Blushweaver, because of her divine Breath, is immortal. Elhokar is not immortal and not able to become immortal with his world's magic system.
Blushweaver, if she were able to continue in a relationship, would choose Lightsong over Elhokar.
Aesudan and Blushweaver both had ambition, meaning Elhokar would be attracted to them. The first relationship ended badly. Why would the second not?
While Lightsong was wise, Elhokar is not skilled, relying on his uncle and luck.
I disagree that Elhokar and Blushweaver could help each other. Blushweaver channels her intentions in distracting ways. For her to help Elhokar channel in productive ways would be the blind leading the blind. Elhokar is not a strong man; he would not be able to help Blushweaver be a strong woman.