Conversation so far:
When did Supergirl first appear in animation?
Supergirl first appeared in Superman/Batman: Apocalypse, a 2010 animated superhero film based on the Superman/Batman comic book storyline.
Was Supergirl never shown in the Superman cartoons?
Supergirl did not appear in any animated Superman cartoons.

Question: Were there any well known voice actors in DC Super hero girls?
Self-contained rewrite: Were there any well known voice actors in the animated movie DC Super hero girls?