Asking why the plan changed is perfectly reasonable especially when they only just joined up because you planned to help that "innocent small family", so changing her mind definitely requires an explanation if she wants them to stick around. Maybe the guy asked wrong or is a bit dumb for not figuring it out, but his reaction wasnt that strange. Rather disappointed she just potentially just threw someone and all those people to theirs deaths. Especially considering her goal was to unite both halves of the faction, How will she do that if all of them die? I hope this is part of some plan and she knows they wont die...