Of course I wish no bad to your Mum, Nic.
I do applaude those Jw's who will take a stand one way or the other. You might remind her gently, that 'absolutely no blood' means many vaccinations, and immunizations would fall in that catagory. For her sake - and yours - though I respect that she obviously is holding closer to what she believes the Bible to say [due to swallowing the WTS line of BS] - you may wish to actually help her to work through the list, point on point, and perhaps aid her to make the decisions. In this way, if she would allow it, you may be able to get her 'liberallized' on a few key components that the WTS is allowing now. It could prove valuable in the future.
Good luck.
Jeff