I'm really sorry for your sister, it sounds like your brother is just clueless/inconsiderate and doing whatever the girlfriend wants and she doesn't care about anyone else in your family. The girlfriend is lucky she has never had to experience anything so traumatic as your sister has and probably has no idea what a horrible thing she is doing. I can't imagine not caring about causing a family member so much pain over a name, when there are so many nice names out there to use..