In fact, it seems like she has NO severe mental delay, just educational delay and perhaps mild mental delay. She walks normally as a usual child.
Update Dec 2021, from someone who met both Hazel & Ivory: They are really tiny young ladies, so sweet and giggly. They stopped by the orphanage director’s office to say hello. Hazel is practically without special needs, and she is inseparable from Ivory. Since Ivory is blind, Hazel watches out for her little “sister”. So sweet.