In my experience this match-up is tricky due to Nu can keep plat where she wants. Items in the match-up the favour has to go to missiles then bombs. This is because they can force nu to block which means a free run up for plat allowing you to apply pressure, Cat hammer can be okay but be careful when you jump because Nu can potentially 2D and catch it. The best approach for plat without these items is to slowly jump barrier, or dash barrier (if good enough to do so)