B.B.
We haven't had a virus just like what you have described, but certainly have had viruses that had few symptoms aside from a fever that persisted for several days.
You took her to the doctor and they checked everything out, so at this point, waiting seems like all you can do.
It can be hard for parents to remember that fever is not a scary or dangerous thing. Fever is a sign that your child's immune system is working on eliminating this virus; it is a carefully arranged and healthy response of the human body.
With that in mind, the decision to medicate a fever should be based on your child's behavior more than the number on the thermometer. If your child is miserable, then absolutely give the Advil, but if she has a fever and is comfortable, you might think about holding off on the meds and letting her body do what it is doing. Suppressing the fever is, in a way, suppressing the body's natural way of fighting the pathogen. Keeping your daughter well-hydrated and allowing her to rest is more effective than Advil in term of getting rid of the virus. Again, if she is uncomfortable, give her the meds, but if not, there is not a magic number above which a fever must be medicated and a 103.5 degree fever is not dangerous in and of itself.
Here's an article that might be helpful for this:
http://www.nytimes.com/2011/01/11/health/11klass.html
I hope that she gets to feeling better soon!