To return to Pauline, I think Pauline is now known for being a singer and a mayor. That is what her moveset should be based on if she gets in right now.
Maybe she has special attacks where she sings and makes characters within a certain vicinity taunt, so they're like dancing. Maybe in her final smash, she commands a fleet of New Donk City taxi cabs to run over opponents like Yoshi's Final Smash.
Standard special: Girder - Lay down a girder. Temporarily adds to the stage. If laid down in the air the girder will fall to the ground and can be used for attacks.
Side Special: Hammer Mini Mario: a dual Hammer Mario is sent out. Charge it for more distance.
Up Special: Spring - launch up on a DK spring that falls below. Can be picked up by opponents
Down Special: Chorus - pushes players and items away with no damage, charge pushes them farther. Can be used to absorb or reflect projectiles, though the latter is difficult. No damage.
Final Smash: Jump Up Superstar - the band appears and sings a short chorus while players caught in the attack are shuffled around the busy streets and crowd of New Donk taking damage. Her last note can send them pushed hard off stage.
Standard moves are jabs, music notes, call backs to DK items.
This is how I see her. Medium speed, but light. She's a setup character who can use the mini Marios and girders to control space.
