I was planning to skip the Fire Cavern since everyone already has a GF; unless someone wants to earn their GF before we start? That said, it'd be a bit of a bugger to RP as the FC test only allows the candidate and one SeeD to enter.
Petrify comes from the spell Break I think, which is a mid-level spell, so I'll say that she can pick up enough to junction soon but not immediately.