Is it legal for a special ed teacher to take and share a cell phone picture of a 8 year old with downs syndrome without the student's knowledge and the parent's consent in Maryland?

No. That would be an infringement on the privacy rights of the student. The teacher should be reported to the school administration immediately. She may be able to take photos of students for her own official school purposes but she cannot publish and distribute a child's photo. If the school was to allow a person in to write an article about the school and take photos it would seek the written consent of the parents. The parents should stay on top of this situation to make certain the teacher is both enlightened and reprimanded.

This teacher needs to be educated about her students' right to privacy. She has extremely poor judgment. There is a pervasive attitude in modern life that if you can do something then it must be okay. That is an enormous problem. Think teens sending off nude photos requested by a boy they hardly know- photos that the entire class has on their cellphones by the next morning. Many people cannot discern the difference between the physical ability to do something with whether or not you should do it.