Quoting Photo Assassin:" Seems kind of petty that she'd get mad someone would wish your a day she was born, including her family. ... [snip!] ... YOU" Not downing your sister, but she made the choice, not you. It wasn't like they sent over a marching parade or something."
I agree. Makes me kind of sad actually. It seems something so benign and really, a well-meaning thing to do. I don't celebrate anything either but it's nice when someone tells you "Happy whatever" because it's really just a sign they remember you and care about you.