If you have an OT on staff or a psychologist ask for a consult (with the parent's approval). Things you can try is if you have a weighted blanket or a "quiet" corner in your classroom it can really help. If they're fidgety have them stack books, blocks etc., give them something to do with their body while you're teaching. It can be hard in a classroom with other kids where they're expected to sit all day and be quiet, not touch others and participate. Weighted vests have helped my son a lot in class. If this child does have SPD changes in routine will be very difficult, giving them a 1 -2 min ahead warning that something will be changing i.e. location, class etc., can be helpful.