you got to go to veilstone and that's where she is.
You get your 3rd badge in Veilstone city against Maylene.
you go the the fourth gym in pastora and battle him
hearthome i think
in eterna city
you cant
The mine badge.
== == You get the 8th gym badge in Sunyshore City. Hope this helps
Beat the gym leader
sunyshore
Snowpoint City.
Veilstone City
The third badge is in Goldenrod City.