My three yr old has a red fine bumpy 2.5 circle on her arm i have no idea of what it is?

Ringworm: Sounds like ringworm, which is not a worm, but skin fungus (tinea corporis). Very common & affects even the cleanest families. Google photos of tinea corporis &you will likely see very sharply defined, round, pink/red, scaly patches of skin. Responds to nonprescription antifungal cream but may require a couple weeks. If not improving in a week, see a doctor. Could also be impetigo (bacterial).