2 year old has had a 102 axillary temp for 3 days. not eating well. tired. no other symptoms. should i take her to emergency room?

Not emergency but...: I would NOT take her to the emergency room as this is not an emergency. She almost certainly has a viral illness that will go away on its own. No problem if doesn't eat well for a few days as long as she has adequate fluids- try chicken or vegetable soup. Fever is how the body fights infection so I advise not giving Tylenol (acetaminophen) or other meds to lower fever. If not improving soon see her regular doc.