Children often grind their teeth as they grow-the teeth are searching for the correct way to fit together. It is pointless to have a mouthguard made at this age since you'd be replacing it constantly as she grows. Severe wear of the baby teeth can occur, but your dentist can monitor this at her regular 6 month check ups. The baby teeth will take the brunt of the wear, and she'll probably lose them by the time she's 12. By then, when her new teeth are in, her dentist will check her bite to make sure everything is lined up properly, and refer her to an orthodontist if there is a problem. At that time, if she's still grinding, a mouthpiece can be fitted which should last a while since her growth should have slowed down by then. Stress adds to the grinding problem, but unless there has been a major upheaval in her life, probably is less a cause at this point.