Hopefully one of the professional tests will turn up something definitive. In the interim, your mom is right. It could only help, imo, to use colloidal silver. Hard to give too much on a short term basis, even with one so young. It it were me, I would start off with a couple of ounces or so and then each day thereafter a couple of tablespoons a few times per day. Probably a good idea to take some childrens priobiotics in between the silver.
Let us know how things go and if the tests turn anything up.