Something tells her that it's pointless to ask him how in the hell he even knows about that. She could assume that it's a lucky guess, but not everyone would have reason to assume that Rey, strong or not, could heal faster than a human, mostly thanks to being partially made up of her father's immortal cells. That also isn't something she can see herself ever sharing with a child, though.

"Don't have a 'dominant hand', so it shouldn't be a problem." One more perk to not being human -- you aren't necessarily more inclined towards your right or left.