I found her very easy to morph, possibly because I made her. An example of a quite different looking face morph I made is here (warning: nudity). Cage has also made some. I suspect the problem is that Antonia was designed to be morphed using quite different morphing techniques than what's common in the community.

Could be.  However, I don't think Antonia looks very different in those two morphs.  Still has a long, thin face, with the same nose, lips, and distinctive cheekbones, jawline, and chin. I like to be able to morph figures to look like actual people.  I found that impossible to do with Antonia.