Hello and welcome to HCM,
Are you sure your 12 year has ringworm ? Raised spots arranged in circular manner with central flat area. If yes, then it is ringworm.
When a child is having a ringworm rash
it is advised not to go to public bathing area since it is contagious. Wait until the rash clears off, whole of it until which she'll continue shedding the fungus.
Teach her to keep the area clean and dry, daily laundry is not a necessity.
Hope I helped.