i do prefer aria hardening her heart after all, even though it is nice to see her warm up gradually
but right now isn't the time to warm up and let your defences low, aria currently has to fight for her life, so what she needs now is a strong will, not a heart that is prone to intense emotions, because that can be an extreme weakness, like we've seen in this chapter.
maybe after all that's done, and when aria is finally safe, then she can lay low and relax a bit.