Just thought I'd add my two cents:
That second thing is def. Terra - at least the CG cut scene of her. In the FMV version of FF6 Terra has reddish-blonde hair and it is always pulled back into a ponytail. Plus she's wearing her red outfit; the color is just altered by the sunset.
As for FF5, Krile is the name of the blonde girl (or Cara if you count the ROM version) and in the CG version of that game, both Reina and Faris have reddish hair. But that shot doesn't appear anywhere in that game, and it does happen in FF6.
Melloncollie - good luck on your costume - I love old-school FF costumes! Here's an image: http://www.zellfantasy.it/ff6/terra.jpg