There's a noticeable hesitation before she answers but maybe it's just because she's in the process of rending their current prey. Once she's finished and the ayakashi's slain, she answers.

Since this summer. It was like this when I first came here as a shinki and had already healed like this.

Had Ayumu mentioned she used to be a shinki herself until very recently? She can't remember and right now, she's trying to quell an instinctive surge of panic as her mind threatens to wander to exactly when and how that particular damage had come to be. For a moment, Ayumu looks a bit lost and vulnerable herself.

However, it'd occurred, it's very clear it's a highly unpleasant memory, to say the least.