You can give her tiny mushrooms or big mushrooms.
Route 18. Far West of the route.
You can find relicanth on route 4
when you have beaten the Pokemon league, you can get to black city, and on the route between nimbasa and black city,(not route 16, the route after that)you can find the poke-transfer lab, you get told how to do the rest when you get there.
you get it in route 5
I think route 16
route 1
Route 2,3 or dreamyard
route nine
You can find it on route 18.
there has to be a pokemon outbreak for it to work, s/he is in route 2
you can find vullaby in route 10 11 victory road and the village bridge only in pokemon black.
at the daycare route 3 or 4, or the route after striaton city