It's Annie who wanted to help Jeanne for some dumb reason.
Parley, too, but Annie was the one who strongarmed everyone into helping her.
Even Parley, if you think about it, would have never helped if she hadn't been pulled into it by accident.
Of course it's all Annie's fault!
This entire thing was unnecessary. She could have just ignored her like everyone else.
In the end Jeanne didn't even remember her time as a murderghost when she moved on, so what the hell was even achieved? Nothing at all.
To top it off, time will tell if this was not actually a terrible mistake that starts a war between court and forest.
Annie took a stable situation everyone was happy with and turned it unstable by almost sacrificing two lives, just because she wanted to feel good about herself.
Her friends are stupid for helping her, too, sure, but Kat doesn't have many friends and Ayilu was basically bribed with a name.