I think it unlikely we'll meet her since Iron Bull is the official Qun intelligence gatherer for the part of Thedas we are in. I suppose he might mention her.
Of course she could still be running solo. I doubt her superiors were very pleased with her actions in MoA; they had specifically ordered her not to interfere. Either this was because they didn't want to alert the Orlesians to the value of the information on offer, or in fact it was a set up by them and that guy who was allegedly a Tal-Vashoth was in fact a double agent. So either she is back in Par Vollen being re-educated into proper submission to the Qun or has in fact become Tal-Vashoth herself.
However, that said, I suppose she could form some sort of sub-quest involving Iron Bull. He could get orders from his superiors to track her down and we have to decide if we want to help or hinder their plans. The fact that the MoA plot involved Orlais does make a direct link to DAI. If nothing else we may find out more about that plot thread.
Note: Talis and Hawke are likely to be persona non grata with Celene. Duke Prosper was a very close ally and cousin to Celene, one of her chief supporters, so any enthusiasm shown towards his killers, particularly since it was not done as part of the Game, is not likely to make you popular with her.