My daughter has non itchy painless red bumps all over her back arms and legs only what could they be?

Many possibilities. You didn't mention your daughter's age or how big the bumps are, but the most likely possibility is probably bug bites, which aren't necessarily itchy. Since they are widely distributed it's most likely a flying insect, e.g. Mosquitos. It could also be a viral illness or allergic reaction. If symptoms or a fever develop, you should see your doctor or a dermatologist and get a precise diagnosis.