The final dungeon can take on multiple patterns for the bridge gaps. I believe there are 4, though only 2 maps are available. The pattern resets every time you reenter the dungeon, so you can abuse that until you get one of the two mapped patterns.
Maps source: here
The maps highlight the correct path to the final boss.
Leia’s mom, Sonia, needs to be an optional boss fight that takes everything you can muster to even drag your sorry ass to victory against. If she can intimidate the previous game’s final boss, then she’d have no problem spanking 4 uppity youths at once.