I've never played FFVI, but Elsa reminds me of a very Terra-like character.

I really think Rapunzel would be great as a healer/white mage. Her Limit Break could be 'Sun Song' and it would completely restore HP/MP of the party. Of course, her story would stay the same (kidnapped, has no idea who she really is) and then later she'd ascend the throne of her kingdom.