No, a legal name change does not legally void the order: the victim is still the same person, regardless of his/her name. Practically, the name change may make it more difficult to enforce: e.g. say that the defendant violates the order and the victim calls the police and shows them the order--the police may say, "this order is for Jane Doe, but you're Sarah Roe; it's not your order." Of course, you could then show documentation that you were Jane Doe, but it would be better to go back to court and get the order modified or amended to reflect the new name.