You need to attend to the Ampharos' trouble first. She is more concerned about the Ampharos than battling a trainer at the moment. Go to the Cianwood pharmacy and get the potion to heal ampharos.
Jasmine is the Olivine City Gym leader
talk to jasmine in the lighthouse at olivine city and then go to cianwood and talk to the pharmasist
You can get to Jasmine but this time beat Chuck and obtain HM Fly, go back to Olivine City, Jasmine uses the secret potion to heal Ampharos and you can beat her at the gym.
Go back to Olivine City and give the medicine to Jasmine. Then fight her at the gym.
I think you made a fault with your spellling and games the gymleader from Saffron is in Olivine city in HeartGold and SoulSilver, But in Diamond and Pearl Jasmine, the gymleader from Olivine city is in Sunyshore city, She is on a journey...
To battle Gym Leader Jasmine of the Olivine City Gym, you must have gotten the SecretPotion and healed the Ampharos.
In Pokémon HeartGold and SoulSilver, you get Jasmine's Phone Number by going into the café in Olivine City any day between 1 PM and 2 PM. Talk to her there and she'll add her number to your Pokégear.You can get her number by going to Olivine City diner any day between 13:00-14:00
Get the secretpotion from a guy there and go back to Olivine in the lighthouse and cure the Ampharos in lighthouse and then battle Jasmine
Olivine city.
At least level 30, but I suggest you use Fire or Water types because she specializes in Steel type.
help jasmine at the light house
The Lighthouse is in Olivine City.