It is a situation that needs to be checked by a doctor. Continuing to injure the same area is not good.
This also shows the cause of the stress fracture is not being addressed.
3 stress fractures in the same spot of the same foot sounds like a running technique issue. Until the cause of the stress fracture is addressed it will continue to happen and not heal.
The longer she trains on an injury the longer it will take to ultimately heal.
She could reach her body’s tolerance to train with the injury before the season is completed and not perform at an acceptable level and not end up being able to train/complete.