@J Scott , what is the site like? Any views and if so which way? Seems like the main living spaces are all out back. The combo of stairs and mud room might block off the entry and make it feel smaller than it is being tucked off to the side. It's a fairly symmetrical exterior so people might expect a central hall type space....not saying its good or bad, you can make either work.
I think you might want to look a little more at the stair location, make sure it's going to fit there. Personally I'd try and move it off to the side somewhere so you can have a little more visual connection to the front.
The only other comment would be to take a look at how the sun moves across, do you get daylight throughout the day or will the great room only be day lit in the am or pm?
She's done a good job with the sketching, have you looked at Sketchup at all? Lot of fun for modeling early ideas, not a really steep learning curve and I think they still have a free version.
(I know my profile says architect...I'm not registered and have yet to figure out how to put "designer"....my disclaimer)