How to heal shin splints for kids?

FOOT STRUCTURE. Have a podiatrist check the foot structure. Abnormally flattened feet can be a contributing factor.
Ice, rest. I would recommend avoiding the offending activity. Also, use of ice and advil (ibuprofen) will be helpful you should not play if you are limping or having severe pain.
Rest. The simple answer is rest. Rest can take awhile though, so to speed it up i suggest: 1) anti-inflammatories 2) pt/stretching 3) good shoe wear/arch-supports 4) proper training.