Catrina wasn't allowed to have a cute little backpack, mainly because of the flame. What she was allowed though was to assist in foraging via melting some snow with her little flame. Sure, Catrina managed to survive the wilderness last time, but that was likely because of sheer dumb luck.

"Hey no problem, we still need to get you ready to have a meeting with Polteageist and getting you over your fear of ghosts."

Good news though, Catrina is leaving a nice melted path through the snow, so it should be easy to follow back to civilization. At least it isn't a melted wax trail...that's the plus.