If you're talking about that adventurer in plate that got brought out of the cave, you might want to take a closer look at page 6.
Chest go out. Waist go in. Hips go out. Exposed crotch area with no protrusion. That is obviously a girl.
What kind of logic do you need to find it weird to be thanked for saving someones life (by said savee)? Feels like it is common courtesy, and particularly someone who has dealt in death would know it (didnt he even tag along a hero for a while?).