There are several things you could do to make this cabin look more like the original. I would get rid of the foundation, use the short wall on the lower floor, use full height stone for the siding on lower floor and choose a white wood siding to simulate the garage doors. The third column under the porch also appears to be missing.

Next extend the second floor to fully cover the bottom floor. That would give you more room to add a second bedroom and the stairs to the third floor, Then put a third bedroom above.

I haven't built much yet in TS4 but built extensively in TS2 and I have always followed the floor plan as closely as possible then did the exterior. You've done a really good job on it as is.

Thank you! I'm trying some of your ideas now and taking a closer look at the floor plans. Believe it or not, I barely looked at the floor plans. That's really a big help.