Perhaps they are one and the same. Different worlds do have different sorts of creatures, so perhaps animals are from my world, and pokemon are from yours.

[It wouldn't surprise her, to be honest.]

And I certainly agree with you there. There are far, far more animals than there are people, and thousands of different kinds, as well. If they are analogous then it stands to reason that there should be just as many pokemon. Though, animals don't generally talk, in my experience, while yours seem to at least know their names.