Since it seems Wyrdeer & Basculegion are noble Pokemon (albeit, maybe not ones you have to fight like Kleavor) it kind of feels more like none of the Noble pokemon are generation 4.I bet all Noble Pokémon are Generation 4 and the new Hisuian forms and newly introduced evolutions, so it could be Froslass, Wormadam, Vespiquen, Blissey (since Happiny is introduced in Gen 4), or a Hisuian form or, as you said, a new regional evolution (or standard evolution, either works) for any female-exclusive species.
Hisuian Mandibuzz (though that don't fit that well for a "lady" description), an evolution for Illumise (with an evolution for Volbeat), or even taking the word "ladybug" literally and have a Ledian evolution that have a feminine design and this Noble one in particular is female.
Like Scyther's at least in the Platinum Dex, I guess? But none of the new pokemon or forms have been for actual gen 4 pokemon (or their immediate family).