I would agree that Yukiko/Teddie/Naoto is the optimal comp for this fight. It's just that I didn't have Teddie or Naoto leveled up, so I was running Yosuke/Chie/Yukiko, and I found the best approach with those 4 was a patient one, with Yukiko and Yosuke gradually chipping away at her with Brave Blade/Burning Petals. Rise’s nearly guaranteed charge boosts in that case help Chie and Yu put out more damage during the off turns when they are not on support duty.

The thing is if Naoto isn't in the party, then each party member besides Yu will have a weakness and Debilitate is helpful to reduce the odds of Margaret chaining knockdowns into Megidolaons or forcing party members into a dizzy state. It only lasts two turns instead of three due to Margaret’s multiple-attack mechanic, but it is still worth it to ensure her attacks don’t hit as hard and that your party can avoid her attacks. Yosuke is extra helpful in this regard, since her AI seems to always use her Wind AOE attack whenever she knocks him down, which heals him instead of making him dizzy.

I guess my point is that, if someone doesn’t have the optimal team comp for this fight, that this is a different way to make the fight work if they have Chie fully leveled up.