Normally id take a shot and recommend a broody hen, specifically a silkie to hatch any eggs. HA! The egg is as big as the bird, that would be really funny.
I don't know much about a EMU egg, but I would put it back in the incubator and warm it back up. Then candle it if possible. If its alive you should see movement.
I don't know if you can do this, cause the shell is so thick.