Crystal has joint legal custody.
She has as much access to the children's school records, medical records, etc as Ronald does.
Crystal could call HaLeigh's teachers, schedule parent-teacher conferences, request that a duplicate report card be sent to her, etc. That is HER RIGHT as HaLeigh's mother. She simply needed to be that mother. If she makes the choice not to assert that right, it is no one's fault but her own.
Nancy Grace just seemed shocked that Crystal knew so little about HaLeigh. Even if she didn't know those facts while HaLeigh was in school because Crystal "didn't live there", Crystal has had nearly 7 months to get those answers and build a timeline. I would have been digging for answers to those questions.