With the concepts given the sign-off I moved on to creating orthographic templates to use as measurements for building Four in Maya. There are a few places where the orthographic layout makes Four look thinner than the concept (below) but it was at the orthographic stage where I think I've nailed the feet. I also considered adding ribbon-like tendrils, which would flow and sway with the head. In the wild these could be used to detect air particles, much like the whiskers of numerous mammals, as she lacks nostrils on the front of her snout. If these don't turn out to be worthwhile, then they could easily be left out in theory.
I looked at otters to see how their feet were built for both land and water. And while Four's feet might be a bit shorter than a typical otter's, looking at the two images I find that what I came up with as a bottom-up view has closely matched the feet that came out in the concept design.