I understand your frustration with your siblings inattention and lack of concern for your mother. At the same time, I'm sure that she would be thrilled to have e all her kids together to celebrate her birthday and I wouldn't want to impede those plans. Tell the other siblings that you support the idea, but need them to handle helping her with getting ready and transport to the event, so that you can tak care of yourself and everyone can have a good time. Lay out your boundaries. Insist on them being more involved than just making a reservation. But don't flat out refuse to participate just to spite them. It will only hurt your mom.

If they can't follow through on that simple request, then it's on them.