Something that I think is worth mentioning with the recent discussion of Superhumans being infertile, is that it doesn't actually seem to be the case, just like someone said recently on the thread, SH have difficulties to produce offspring given their unique nature once they ascend, essentially becoming their own species. But Aos and Danu were able to have their Children while already being both Spawns, also, WeirdWorld mentioned on a Stream after the update, that two Superhuman successfully having an offspring, would result on either a Pure Human or a Monster, but never a Superhuman from birth.
So, apparently as long both Sups are from the same trait, they could potentially be able to reproduce, but that's particularly difficult since most supers are Mutts, with a ton of different traits. There is also fantasy, who seem to be able to just produce offspring with anything, like Glae does, but that's other deal entirely.