QueenofAllThings ~~ If I remember correctly, somewhere in the thread you said that Grandmother had spent all her considerable amount of money in virtually record time which leaves your own mother (and Dad I presume) to pay for virtually all her expenses. I think it's time for the other sisters to step up to the plate here.
Maybe they don't want to deal with her (and that's okay), but that doesn't mean the TOTAL burden should be on your mother. If the family thinks it's important enough for Grandma to go to her son's memorial service, then they should be the ones footing the bill, or at least providing two thirds of the costs.
Grandma, with her past spending habits, is responsible for this dilemma. Maybe it's time someone just told her the truth. "Yes, we know you want to go. But you don't have the money to go and we don't have the money to send you! So it's just not going to be possible."