Arrived in the mail earlier tonight (how does that work—I thought you had to be served in-person, but whatevs).
Yes, if the papers have been filed with the court then you have to be served by an agent of the court, in person. This is the same in all states as far as I know. Who sent the papers to you? If they came from her L then they may just be for your review and they haven't officially been filed yet. I know it's a real gut punch to get those papers, but hang in there, it'll pass!