Here is the link to the Blue Book instructions on how to evalutate diabetes as a disabling condition. Your friend would have to have some severe side effects from the illness.
http://www.socialsecurity.gov/disabi...rine-Adult.htm
The most important thing for her now at this point is to do whatever it takes to keep tight control on her glucose level - work closely with her diabetes educator - and stay on her health insurance plan. There may come a day that she will not be able to work any more, but if she can drag herself to work 30 hours a week, SSA will not find her disabled.