Dearest Mark... may you have peace.
Please know that what I am about to say is, I think, quite different from what these kind folks are telling you to do... but it will be the truth. Dear one, whatever you do, it must be what you MOTHER wishes. And if taking no blood is her wish (even if she has been duped into believing it's validity), it is still her wish.
The reason I am writing this to you, is because I lost both of my parents: my mom, in 1977 on my 18th birthday, and my dad in 1988. I also underwent a lengthy and grueling illness with my son, who too almost died. What I learned was:
It is the person dying whose wishes MUST be respected, regardless of what you think or feel.
You see, we who live on, tend to do what seems to be best for US... so that we can continue living in relative peace. If we are against blood, etc., then we want the ill to respect OUR wishes and abstain. That is why the JWs are in the room in the first place. If we are not against it, or some other thing, then we want to ill to respect our wishes... and continue living... for OUR peace... irregardless of what such a decision may do to THEIR conscience... and continued quality of life. If they live, dear one, THEY have to live with their decisions, not us.
What you might wish to consider doing then, is asking everyone to leave the room so that your mom can speak freely... and then asking HER what her desire is. Now, you might be tempted during this time to try and persuade her to change her belief, but I must ask you, would you be any different from those sitting the room forcing THEIR beliefs on her? It is her life; thus, it is her decision... right or wrong as it may be.
Everyone one of us have certain desires that we wish to have respected and fulfilled when the time comes that we are in such a position. Some folks want to be buried; others cremated. Some want their ashes in an urn; others, scattered to the wind. And everyone of us here would give all that we had if we could know that such desires WOULD be carried out... just as WE wish them to be. But all too often, people get sick and/or die... and what THEY desired is completely, and sometimes utterly, disregarded. THAT, though, dear one, is NOT love. Love... does not look out for it's OWN interest, but does unto others as one would have done unto themself.
So what if so-and-so wants his body kryogencially perserved? If he has the money, so be it. So what if so-and-so wants to buried on top of her husband so that they are 'together forever'? Biblically, folks made all kinds of requests: to have their bones returned to their homeland; to not be given drugs so as not to obscure the point of the issue, etc. And folks today have requests. They have a right to make them; such requests are theirs and should be respected.
So, my dear, please... do not consider doing ANYTHING... other than what your mother wishes. And you must ask HER to determine that... and RESPECT her answer, whatever it may be. Even if you don't agree with it. It is, after all, her life.
I bid you peace.
Your servant and a slave of Christ,