[Leia keeps her hand on his arm despite his attempts to shake it off, still partially because she's worried he's about to fall over, but also because in the back of her mind, she's aware this is the first time she's actually touched Ben. So out of that concern and out of not wanting to let go of him just yet, she keeps her hand on his arm.]

Tell me why it matters first.

[Not that she plans on divulging any names really, since two can play at that game, but his fixation on it is something she doesn't fully understand. She's assuming that he just wants his own lightsaber to use and is trying to figure out how he can get a new one.]

I haven't known you to be at all concerned about me during our time here. Why is this different?