We don’t just want to create the best desktop environment for the Raspberry Pi: we want to create the best desktop environment, period. There is no learning curve, and no need to tweak her schoolwork to run on two subtly different operating systems.
She can move back and forth between her computing class or after-school club and home, using exactly the same productivity software and programming tools, in exactly the same desktop environment.
Why do we think this is worth doing? Two reasons: