So sorry to hear of what is going on... I dont know what it is with mothers, cause I had a dilly.. but they seem to favor one over the other and especially since the other, in your case, is a JW.. more trustworthy, more reliable, more knowledgable, and on and on...
If your mom will take financial matters over for your gram, tell her to look into it before hand (talk to the income tax dept, etc) cause if and when something happens to gran, your mom will be responsible for monies owing AFTER she dies i.e. Income tax, IRA, etc. and if there are no monies left to pay bills, your mom would be liable to pay them...and perhaps it would be better if the lawyer took care of this end of the business.. as far as the medical end, your gran can do up a living will as per her wishes and no one can dispute what she really wanted.... the elders would have nothing to do with this.... .. this way your mom would not be upset and tell her not to be.... people (relatives) do strange things when it comes to making decisions based on health and money issues...