I just had a #ttrpg / #dnd thought:
Most living, biological beings of the "Material Plane" are strongly shaped by evolutionary forces. We are descended from countless generations of other creatures whose selfish genes (or the equivalent) desired to propagate, and thus made their host creatures strongly motivated to have offspring. Individuals can of course differ, but all in all these behavioral imperatives are pretty strong.
But what if fey/fairies and similar spirits do not have the same evolutionary drives? What if fey "parents" do not pass on some equivalent of "DNA" to their children? What if the offspring of fey is not shaped by the parents' essence, but either their conscious decisions or some environmental factors?
Fey could still be motivated to create offspring. Perhaps they want companions, or servants, or tools. Perhaps the notion strikes them as interesting, or funny. But their intrinsic motivations and behavior regarding their offspring are going to be very different from those of, say, humans.