First of all, tell your daughter to throw that damned Fosamax out - it is a truly evil drug. It does not build proper bones but instead builds brittle bone growth that makes the bones even weaker and it can have horrific side effects which can result in permanent damage to the jaws as well as the spine - and in time can cause permanent paralysis. I was able to get my 84 year old aunt to stop taking Fosamax a few years ago just in time. She was progressively having problems getting out of bed or standing up and was in terrible pain. She stopped taking Fosamax and begin to address osteoporois naturally and made a complete recovery. See my article on bone drugs:
Now, as for your original question, yes colloidal silver swished in the mouth and rubbed into the gums can help. She can also use a good natural toothpaste such as Jason's Toothpaste with Tea Tree Oil, or even use the Colloidal Silver Skin and Scalp bar to brush her teeth and gums with. I also suggest using oil of oregano rubbed into the gums. Oil of oregano is a bit strong without diluting it, so I suggest diluting it 50/50 with grapeseed oil (or virgin olive oil or safflower oil if grapeseed oil is not easily obtainable). While those suggestions will likely provide some relief and lead to healthier teeth and gums, the most important thing to do is to far far away from Fosamax and any other bone drugs!