My 3 Year Old Daughter Woke Up With The Left

My 3 year old daughter woke up with the left side of her face reddish this morning... the red subsided some on the cheek but her left temple stayed slightly swollen between her eye and ear and was red I noticed a slight fever in the red area. Took her temperature and was 98.9, she ate normally today and drank plenty of fluids, had plenty of energy. Never complained of pain, even when keeping an eye on her red mark I touched it to see if she would complain of pain and asked her if it hurt. I gave her about 2.5ml of benadryl and some ibuprofen a couple times throughout the day but the red area never went away. Her throat doesn't hurt and her ears seem fine when I tugged on them slightly. She went to bed tonight with the red slightly swollen area still on her face. I've researched the mark but nothing seems to match her symptoms. Also no facial injury or any kind of accident that would warrant a red swollen area in the face