I am a former teacher. The first thing that came to my mind is to make sure the straps are wide enough and strong enough. School bags can get very heavy. Thin straps cut into your hands or shoulders. Make sure the straps are long enough so the bag can be carried on her shoulder. I liked straps about 2 inches wide. I liked a zippered pocket or two for keys, personal items, and other small items that could get lost or misplaced. I got to the point where my bag was my purse. Teachers always have pens, pencils, paper clips, etcetera in their bags. My favorite bag had a zipper to close the main compartment and a flap to cover the whole thing including outside compartments, kind of like a messenger bag, to keep things dry and secure in bad weather. I did not like outside compartments that did not close because things could fall out of the bag when it fell over.