5 month old with fever

Samantha
My baby is about 5 months old and on Thursday afternoon she developed a fever. It's been 2 days now with no sign of the fever letting up. It's not a very high fever of 101.5, but it did hit a little over 102 last night. My parents insist it's nothing to worry about, but first time mom here and I'm worried. :P Any of you ladies have any advice as to what to do?