I suspect my 15 year old daughter has an ear infection. can we treat without prescribed medication? is there anything we can buy over the counter?

Depends: There are a few middle ear infections that are triggered by viruses and heal on their own within a few days.Simple pain control is all that would be a benefit. However, true pus generating middle ear infections are caused by bacteria & require antibiotics for cure. Untreated they can go on to cause complications including mastoid infections/hearing loss. Have it evaluated soon if not improved