All previous advice is right on! Have her check with her Dr. first!!! The LDS will make her get a medical OK before she can dive. Most Drs. will give an OK if they understand how she plans on diving, she will need extra help with certain tasks and if the Dr knows HOW she plans on overcomming these probs she should be OK. I needed to do just that, My Dr said no way you can carry all that weight with your condidtion (Muscular Dystrophy) after I explained HOW I dive: buddy carries gear to and from, I suit up at the edge of boat (or in water) so no walking with tank on back, I take off all gear in water and pass it up to crew on boat (Once again no weight to support) Plus I ALWAYS INFORM EVERYONE of the crew of my condidtion so they KNOW to look out for me and that I need extra help. She will probably need someone to carry her equipement help her put on and take off her gear, but if she has pain swimming, movin with gear on or climibing up/down ladders it might be a no go. But if she can go to the LDS and speak with the Inst about her limits (pain threshold and what causes her discomfort) and ask them what Diving will require (as far as physical demends) they will be a better guide as to weather or not she will be able to dive.
One of the ways she may find easier on her disk is to not don or off her equipement on land but put on and remove BC and gear in the water, as long as the movements to do so do not cause her pain.
GOOD LUCK hopefully this helps
WAC