Suggest Treatment For Posterior Tibial Tendinitis

My daughter is 12 and runs cross-country. She runs approx 5 miles per day 5 days a week. An MRI shows she has posterior tibial tendinitis caused by an ill fitting pair of running shoes. But it also shows that every bone in her foot is bruised. Obviously it is bilateral. A few questions: 1. Is this common in youth runners? 2. Does bruising foot bones result in shorter stature? 3. How long can a kid run with bruised feet before it adversely affects her height. She is hitting a growth spurt now. She has grown over an inch in 2 months.