She did have advanced picklock, but I decided locksmith was not worth the points. When I played Tellik, I used locksmith to copy the Empress's key and plunder that chest repeatedly. But even with a non-crumbling copy of that key, you still only have 50% success rate each pass with looting the letter. Thelana had a much more efficient method of gold acquisition that paid off 100% of the time, and had a slightly higher pay out each pass.