>>12614781>>12614793>>12614809We can't know for sure. From what I can make of it, an Egg Group is really more along the lines of an umbrella term simply used to categorize certain Pokémon shown to be capable of inter-breeding with eachother. This doesn't mean they have to share similar physical characteristics; hell, look at Skitty and Wailord for example.
The biology of Pokémon, Gardevoir included, could be infinitely more complex than anything we know of. In the end, who knows? Everything's up for grabs...
