Board Thread:Questions and Answers/@comment-26335938-20150422171926/@comment-10733658-20150422173209

Pretty much. Eto, Yoshimura, and Kaneki are a good example of how a Ghoul develops more "limbs" as their powers increase. (Or how Nishiki's tail has gotten much larger.)

Touka probably hasn't pushed her powers to develop further, so still has her default.