...in 'Morgoth's Ring' there is the line "we hear of few deeds of lust among
them." Perhaps that means very few indeed, but it definitely doesn't say
'we hear of NO deeds of lust among them.' And by the nature of things we
should imagine that the affairs of men are less tidy than those of the
Eldar.
And we should recall that the Princes of Dol Amroth may
well be the products of rape. For Mithrellas to abandon her husband and
children suggests something very wrong about the situation. In 'Turin
among the Outlaws' Turin rescues a woman from an attempted rape, and she all
but says 'take me, I'm yours!' (of course she assumes that he'll slaughter the
surviving bandit and present her father with a couple of heads to make it
official).
But these are quibbles. You are of course correct,
expect that perhaps Eowyn's despair was so great that she wouldn't have cared
about Aragorn's
attachments.