I know there’s no way to predict a specific item coming up. In fact, I once spent about 30,000 blood shards, and millions of gold trying to get a Reduced Cooldown on a weapon. Finally I threw the weapon away.
However, is there any link between the level I am and the quality or level of the gear I get? I’ve tried from T1 to T17 and can’t really see any difference.
So your character level and class determines what kadala can give you, but once you get to 70 she can give you all items in your class drop pool. Paragon level is irrelevant, as is game difficulty level afaik.