It hurts.
It's not that Lusilla's never felt pain before. Stuff happens. Sometimes whatever animal she's hunting will get in a hit, or she'll slip with her knife, or any of a thousand other ways to pick up a minor injury that come up in the day to day.
But usually when she gets hurt it goes away. Slowly, for the bigger hurts, but it's generally over in less than a minute, and she can feel it getting better.
She can't feel this getting better. It hurts and it's not going away.
She wants to cry out, but her chest hurts more when it moves, so, that's maybe a bad plan.