Thanks Ladies for the kind words. You all make me feel a bit better. I agree she is childish and selfish and making this all about herself, and the worst is, if she just thought about it and gave it some time, I'm sure she would actually like the name. I'm pretty sure this is just about getting attention, and getting her own way. This type of behaviour is not new for her, it just comes at a bad time. I agree she will just hurt the people she loves, and it is incredibly sad, but she has always been very serious about principles and what is right (in her opinion) and is so stubborn that, once she has convinced herself that her "cause" is right and just, and the right thing to do, no-one and nothing will sway her even if she destroys relationships. She has already alienated most people around her. And she has now convinced herself that she is doing the right thing for her unborn grandchild, who can't yet speak up for herself.
At the moment I'm dealing with this as a tantrum. I'm upbeat when we speak and I don't give the topic any attention, and if it comes up I just say that the topic is closed, and I move on. Unfortunately, where I was not 100% sure about the name or spelling, she has put me in a position where I can no longer change my mind because that will make it look like I gave in to her demands. I hate being in this position, the name of a much loved child (and grandchild) should not be chosen under such circumstances.