CharSloth, I have done hospice volunteer work. If your bf is very close to his grandmother, he needs to visit her often and be there for her when he can. As far as your involvement goes, if you know the grandmother, just be yourself. There is nothing more depressing for a dying person than oozing with sympathies. If she is still alert, she likely is prepared more than you or your bf would believe. Older people have a lot of moxie when facing death very often. However,some who have led a disfunctional life, usually have disfunctional families and their deaths are not so healthy. I see no need for you to worry about this. If bf needs someone to listen; you can be that person. It all depends on variables within the particular family.
hugs, bj