You didn’t mention what might be causing your daughter’s injury. Stress injuries are common in athletes, especially when there’s been a recent increase in sports activity or training.
Navicular fractures or stress injuries aren’t rare, but unlike other stress injuries they may require special treatment. Having bilateral navicular injuries is relatively rare.
Most stress fractures get better with rest from the activity and removal or change in any risk factors. Preventing stress injuries or re-injuries is also important. Once again, finding and changing risk factors is the key.
Preventing or correcting training errors is one of the most important ways to avoid injuries. Many stress injuries are the result of sudden increase in frequency, intensity, or duration of practice or play. Worn out equipment (including shoes) is another factor. For the runner, changing from an asphalt to cement surface can be the problem.
Girls face some extra challenges. Many girls diet and restrict calories while training. The result can be a loss of bone density leading to fracture. Whether your daughter is an athlete or not, a close look at diet and nutrition is a good idea in maintaining good bone strength. If she is an athlete, then a careful review of her training methods might be helpful.