Do you have a disease or a high bounty or something that would change the greeting when you talk to the wise woman? If I remember correctly, she gives the topic of the telvanni bride when you open the dialogue window with her. Of you have something that blocks the normal greeting, like a disease or high bounty for example, it might block the topic for you. Try that first.
I can't remember off the top of my head what the topic is, but it's something along the line of special arrangements or something like that.
Try and talk about every topic if you can, because Yeah she should give you the mission to go talk to the tel ahrun slave master who then gives you a mission to get exquisite clothes and telvanni bug musk.
If that doesn't work, you can always console command the next stage of the quest.