I put a point into her proficiency Ninjato/wakizashi/scimitar upon lvl up...

And just picked up my first Wakizashi weapon... and she cant wield it! Even though I put a point into it!!!

On top of that, the item the description says that Druids cant use those weapons...

If Druids cant use those weapon why is the game letting you put a Proficiency point on them!?

Is there a way to fix this or at least undo that point unto something else.

Seems like a HUGE OVERSIGHT by the developers.

Oh!... Man. Ok, I guess I didnt waste a point. Nice.

Strictly speaking, these statements are not connected. If a weapon is allowed to a class, then (ignoring attribute requirements, if any) members of the class can wield it even if they do not have any proficiency points in it. They will do so at a class-specific penalty, so you should prefer weapons you have proficiency in over ones you don't. However, in some cases a magical weapon will offer a perk that makes it worth using despite the proficiency penalty.

No you haven't. You'll find a nice magical Scimitar in Cloakwood and/or Durlag's Tower.