Dropped Tyrana 3 times today. She is not dropping any of the associated quest items.
http://eqbeastiary.allakhazam.com/search.shtml?id=1654
Fish Food Vial
Torn Parchment
Both are required/allude to Shield of the Silent Watch and Princess Lenya. These items *should* be dropping everytime (hazy memory but that is what I recall). Ties into the spawn problems with Marlin who is also a part of this quest.