Lovely and well thought out puukko. I like a thicker handle on these, but I prefer them to taper down significantly in thickness from the palm swell to the blade (like 5/8" or less). It really feels good that way with a chest lever grip. Also it creates a more rectangular section at the front of the handle (instead of round or square), which I think aids fine control for certain tasks.
On your GFs knife, how is the balance? I ask because I am mulling over some designs I've created, and some of them have quite wide blades. I like scandi grinds, but on a wide blade its going to leave a lot of steel in the blade. I imagine it would help chopping somewhat.