You find her in oliveine city
building near Pokemon center on cinnabar island
Wednesday from 10 to 19:59
To the Lake of Rage, which is north of Mahogany town.
there will be a secret door at olivines lighthouse and it will take you to jasmine then go back to the gym then jasmine will battle you
You can find a Steelix in Route 47, Cliff Cave, Mt. Silver, or you can trade any Pokemon with Jasmine.
You have to surf to cianwood, which is south of Olivine, and get the medicine in one of the houses there! Then go to the lighthouse and talk to Jasmine, and voila! Go get that biddys badge!
Defeat Jasmine a olivine city.then youll get iron tail.
You might not have got it yet it is on the poke center's left on cianwood city ( an island)
There were hints for the new Pokemon G/S remakes Heart gold and Soul Silver Because she wanted to participate in the super contest in Sinnoh
go up the stairs until you get to the top then talk to jasmine
After you beat Jasmine you go back to the city with gym leader Morty and to right of it which will lead you to Mohagany Town! Where you will face Pyrce (ice types)!! Hope I helped! :D
u talk to jasmine where ever she is and battle her (WIN) and get her number same goes to Heartgold