I think I like Melindiel and Saninde.
I have Burn Gorman in mind as Saeros and Alfie Allen for Daeron.The sons of Fëanor who were unmarried in the First Age in Middle Earth were Maedhros, Celegorm and Caranthir. So, yes, Maglor had a wife at some point, but when they married or whether or not she went into exile with him or what happened to her is completely unknown. Whether or not SilmFilm Maglor has a wife is, of course, debatable. If we never have any role or side story for her, then....she doesn't need to exist.
Also missing from this list is Saeros. We won't need him in Season 3, but establishing him as part of the court in Doriath might as well happen now. Daeron *has* to be this old; he can be younger. So, Saeros should be a 'maybe' for this Season, with the understanding that we're going to want him eventually.