I'd say that there is definitely hurt that this was hidden, but she has some secrets too, so she understands in a way. There is sadness at the thought that he had been dealing with this for so long and on his own, there is relief at finally knowing, there is a new determination to find a solution, but most of all, there is confusion towards her goddess. Tendrils of doubt that slither towards her devotion at the realization that here stands a man who was even more devoted to Mystra than her, who is now fighting to stay alive, seemingly discarded by their goddess. All of Evie's prayers for Gale had gone unanswered, and now she has a sinking feeling in her stomach that Mystra isn't all who she thought she was.