Any trick to Lady Tairla Mhoire? Could it be messedup?

I have spent 3 days at nights in the GY waiting for this to spawn.

I have tried just hanging out..... I have tried logging off and on every 5 min and watching the spawn reset..... I have tried clearing the spawns.... Nothing seems to work. I have been out there for at least 10 night times and nothing. Is it that rare? I used to see her all the time.