My little girl temperature at 38,9 is high and she has runny nose. has been refusing to eat and she was fine before?

New illness: This is often what happens during an emerging illness. By itself the fever is not a threat but a signal there may be something needing further evaluation. As long as she takes fluids well enough to pee every 6-8 hrs she is hydrated. If she is playful & active at times you can monitor this at home.If she spooks you have her seen.