Suggest Treatment For Ear Infection

My six year old granddaughter has been on Primsol for her sinus infection for 5 days (She is allergic to everything besides that). She has a slight rash 2"x3" area on the back of the neck but the doctor advised to take Benadryl along with the Primsol. She seems to have been fine. Today, we took her in to find that now she has an ear infection as well. She has had no other symptoms and seems to be sleeping well. She seemed cool tonight so we took her temp to find it from 97.5-96.4. I am assuming that it is her infections with some concern that we should stop the Primsol if it is not working. The emergency room did not say to rush in but I still am unsure if there is reason for concern; or should we take turns sleeping to watch her? What would be low for a sleeping 6 yr old?