Jesse got his first tooth at 5.5 months but im sure he was teething for about 2 months prior. They can teeth for months (poor buggers!) before any teeth come through. Id jsut try and give her something nice to chew, a teether, you could even put it in the fridge for a little relief for her.. another good one i found because the teethers seemed too big for Jesse's mouth was wet a washer and put it in the fridge for a little while.. then give it to them to chew on.
Hope this helps.