Milly suposedley a hedgehog

Milly is, or should i say was a human, that some how became a mobian
shes new and doesnt know much about anything, the last thing she could remember remember before appearing on the planet was walking home from school when...*blank*
after and before that she remembers nothing
though she does remember being human, and that her name is milly.
but nothing else, naturaly she's freaked out, and doesnt have a clue, but then later meets sonic and friends who promise to help her get home and return her memmory