O.A.
As another dental hygienist, I agree with Tara. Teeth grinding, although very annoying, is considered "normal" in children who still have their baby teeth. Nobody knows exactly why they do it (I'd never heard of it being linked to too much yeast in the diet, before), but it doesn't mean that they will continue once they get their permanent teeth. I've seen kids who have ground their baby teeth down to little nubbins! Dentists don't normally make bite guards for young children--both because they usually grow out of the grinding habbit and because their teeth are moving and changing so much at this age. If she continues to grind after she gets all her permanent teeth, then a bite guard would be a good idea--you could ask your dentist to make one that fits right--but that's still years away! In the meantime, it wouldn't hurt to have her checked out by a dentist, anyway, if you're really concerned.