My daughter has painfil little blisters in her bottom lip she has been running fevers for four days now what can i do to help her she is 3?

Hand, foot and mouth: Your daughter's symptoms sound like hand, foot, and mouth disease (caused by a virus). She may or may not develop more blisters on her hands and/or feet. It is important that she not get dehydrated. Ibuprofen for pain relief is a good choice. If she starts making less wet diapers (or trips to the potty) she may need IV fluids to rehydrate. Call her doctor if this starts happening.

Stomatitis: Have you checked for similar lesions inside the mouth? If so, she could be suffering from primary herpetic stomatitis, a herpetic viral infection. Be careful to not allow dehydration. As my colleague pointed out, it could be hand/foot/mouth disease, also viral and needs care in the same fashion. Self limiting. Good luck!