with the latest update, there's a tiny shout-out to Rainbow Blitz · 7:33am Aug 28th, 2011
Haven't gone back and looked up the author, but 'the arrow and the cross' series has Twi et. al. traveling to a parallel world where they are colts. Most fall in love with their duplicate but Rainbow thinks there's not room enough for both of them in the sky. Blitz starts calling Dash a filly-faker, and Dash is so upset she creates the term colt-crudder.
So that's the other life, that RD refers to in the middle of chapter six of 'war of another world's conquest'