She means the offer, and her demeanor is serious, if anxious. Even her voice is a lower pitch than she might usually speak with. It means something when Imoen isn't playing up the silly rogue that she intends to be.

"I'm sure. I'm - Jade, what I saw, it was hard. And I know how it hurts. But it's not the first hard thing I've seen. Won't be the last."

She doesn't mean it to trivialize the experience. Hopefully it doesn't sound like it. Imoen just means that she can handle it.