Go in Violet City and into the gym.
The fourth gym leader in Pokemon Soul Silver is in Ecruteak City.
Ecruteak City
in cerulean city
The last gym is in viridian city
Morty is the Gym Leader of the Ecruteak City Pokemon Gym.
The gym is right next to the pokemart you can't miss it.
The Gym is in Violet City. Leader: Faulkner, Flying Type
The last Kanto gym is in Varidian City.
In Blckthorn City
Yes.
in viridian city
you find her in the cerulian city gym