The issue of what Sky actually is, alien or super-powered human, brings up an interesting question that also relates to The Avengers 2, are there mutants in the MCU? Think about it, so far we've only seen 3 types of super heroes/villains: there's the tech &/or training based like Iron Man, Nick Fury, Hawekeye; then there's the accident/created like the Hulk, & the Centipede super soldier, Capt. America; then there's the aliens ala the Asgardian but as of yet I don't think that we've seen a single mutant ie. a human born with super powers yet on either TAS or in the various Marvel movies. This relates to The Avengers 2 because it's been announced that they'll be including Quicksilver and Scarlet Witch who we know are the children of Magneto and are both mutants which makes me wonder if they're going to remain mutants or if mutants don't exist in the MCU and will mean a total rewrite of their origins. The question of mutants in the MCU affects Skye because if they don't it will mean that she's an alien, an experiment in creating super humans from a very young age, of possibly a super human by means of inheriting her powers from parents that had super powers by means of an accident or experiment.