While they both have neck-length hair, Unknown's hair seems to be a little longer than Jun's.
Unknown has a tattoo on her right arm that is very identical to Jin's tattoo, in which Jin recieved as a mark of his Devil gene. This could suggest that Unknown could be of the Mishima bloodline, although this doesn't seem to be likely. Jun on the other hand was highly physic and featured angelic powers, which would have protected her from any evil trying to overwhealm her.
Unknown and Jun both have fringes, on Unknown's fringe seems to mirror that of Jin Kazama.
(I got this from Wikipedia.com)
and can you tell me where I can put my Jun petition so I can get more signatures for it?