My wife is on her third last name (two marriages). It's never been required to touch her birth certificate. What I'd recommend, by the way, is to pay the court for a few extra "true" copies (usually these bear some raised seal or such) of the name change order. You'll have to show these (and in some cases leave a copy) with various people to convince them of the name change. I still have a few marriage certficiates. The FAA for the airplane registration were the most difficult people to deal with.