It's so exciting to imagine Melissa Benoist in dual roles as the Supergirl and Bizarro-Girl.
What would be even fascinating if Supergirl teams up with Power Girl (Supergirl from Earth-two) to fight an even more powerful Bizarro-Girl.
If you don't already know, the creator of Supergirl already introduced the idea of Earth-two the his other Flash TV show and there's even talk about crossover.
The more possible scenario is Supergirl's teaming up with the shapeshifter Martian Manhunter (who changed appearance to Supergirl) and defeat Bizarro-Girl.
What would be a heavenly story is seeing four Melissa Benoists in a screen as Supergirl, Bizarro-Girl, Power Girl and Martian Manhunter.
To wet your appetite, there's work from Deviantart user, ThemagiciansBox for Melissa Benoist clone:
http://themagiciansbox.deviantart.com/a ... -1-5795778
http://themagiciansbox.deviantart.com/a ... 7957791595
http://themagiciansbox.deviantart.com/a ... -579577920