Anyone else's LO get ringworm before?

Pediatrician just confirmed it this morning. It started out as a red mark that I assumed was a rash. Then it turned bumpy, I thought dried skin. But a month later, it's still there, so we brought it up at a flu shot visit.
I feel like an a$$ for not bringing it up earlier. Surprisingly, it has not spread and is in only one spot, that's always covered. Knock on wood, her sister has not gotten it, despite the fact that I bathe them together.

Will be stripping both their sheets tonight and bathing separately till I'm sure it's gone.

Any other tips? I think it's contagious by contact and contact through clothing / towels etc. Since it's on her shoulder and always covered I'm assuming no issues with sharing toys. It'll be hard to prevent big sister from hugging her though!