I believe that she is referring to the book the evidence that you have rightfully brought up are not corroborated enough.
1) Ariane statement "i think she is expecting you" is no proof by any means that she was aware that the warden is coming,in fact without the ring she say that she was curious to see if was truly the Warden,proof that she was unsure, so why risk to abandon this personal gift and not give the gift to the warden directly hand by hand?
2) The same statement is said by her for the Orlesian Warden, in which she say "you i do not know", but then she left this supposed gift to someone that she doesn't even know? a gift for a stranger? and for what?
This is why i do not believe that she has left any gift to the Warden,but then again the entire premise doesn't make sense,because even if she left something the plot line is dropped.
As i said, it doesn't make sense given she put and ,also as i said the warden had no interest in this book in first place ,it had no value for him/her.
1)Ariane statment isn't proof but it pretty much indicates that and then morrigan statment confirms she was waiting on you , also she says she remained to see if that was truly the warden and this is line for the warden that romanced her ,for those who didn't romance her she says she waited this long because she was curious.So in both cases she knew we were coming for her.
2)Gifts aren't only given to friends or family ,as for why i rly can't tell you what intentions she had ,all i know that she says every warden would be interested in it.
Well yes (so is pretty much hof) but still as i said there is nothing that excludes giving the warden some sort of clue/leads how to deal with the calling and there are even some hints (note hint not proof).