I would also wager a guess that Valar do not have the same
emotions that, for instance, mortals do, at least not in the same way. Manwë
and Varda, for example, are supposed to be married, but do they act as husband
and wife of Humans would? Can they have children in the same way? Do they even
desire to? I'm not sure they do.
Since we know of one Ainu (Melian) who was able to assume physical form and
conceive a child with Elwe, I wonder if she's the only one to have done this
(or at least considered it)? Does at least one of the couple need to be
of the Children of Illuvatar? Does Ungoliant, as an evil Ainu spirit who
conceived offspring,
count?