Mirabelle is lower level than everyone else

[Utzad]

Even on a fresh loop she levels up later than Odile or Isabeau. Is this supposed to be the case? I'm still only in act two, so is it story related?

[brickey.8]

This is supposed to be the case, it's hard coded. If I remember right it's not even just a case of starting a little behind the others, she actually needs more XP per level.

There's no specific plot reason for this, but it's supposed to present the illusion of being the endgame of an JRPG and it's pretty frequent for the party members to be uneven levels in those games (either due to joining at the wrong level, or people being dead when you kill a boss).