I got the “Memorial for Firstborn Trahearne” letter from Warden Leide, and when I talked to him he gave me the “Events in Maguuma” letter from Ridhais. However, it’s been many days, and she never showed up in my home instance. This is all on a character that has completed Hearts and Minds.
Edit: this is on a level 80 Norn Ranger on Crystal Desert.
Further edit: never mind. I’ve been playing this game since it came out and never actually set foot in the Norn home instance; I’ve been thinking it was Knut’s loft this whole time. I never would have noticed that that door went anywhere if I hadn’t looked it up.