The contrast between her whole heartfelt emotional arc about her identity and revealing that she's not really their old friend to all the people her host's body was friends with when she was a kid was great.
She was sweet, and ingenious, and maybe a little bit mischievous, but overall overwhelmingly a kind person who ended up getting elected Witchlight Monarch.
And so she ended up slipping away from the group while they explored the hall of mirrors, intentionally luring out the culprit by making herself sad and dredging up her regrets.
She then proceeded to somehow manage to grapple Sowpig and wrestle her out of the hall of mirrors and, uh, almost get knocked unconscious in the process, but STILL
It was all for naught since Sowpig had a "I can do whatever I want permit" as it turned out but it was a great characterization moment for Jeanne and foreshadowing what she's like when it's time for Serious Business
Flash forward a level or so, when we're actually in the Feywild and discussing the problem of how to deal with a gang of harengon who steal happy memories.
So she very cheerfully suggested, "well then, why don't we just set fire to the area surrounding their base in strategic locations to funnel them into a singular location and make it easier to kill every last one of them?"
Now it ended up halfway backfiring because they forgot bnuuys have good hearing and all their visual stealth didn't make up for how creaky the causeways were
doom had to miss the last session, but since said session was the trial of agdon longscarf and Jeanne had just carved the J on him in the previous session, it was pretty easy to handwave that Jeanne wasn't allowed to be part of the trial because of said scarring
there is a reason why Jeanne is chaotic neutral rather than chaotic good