Holy Crap - I just realized there's a bunch of evidence to Pixie not being real.
The original solicitation for issue 1# mentions Glob, Armor, Anole and Rockslide - not Pixie.
Not only that - Armor sends Pixie to get Cannonball to a doctor in issue 10 of Disassembled.
Add to that the Pixie tries to read Glob's book like the twins did, and I'm almost certain at this point.