What follower mod are you using? I use AFT and had this issue a few times but manage to fix it on my own. I hope you have a save that is right before you encounter her, because that will help. One way to fix it is to reload before encountering her and making sure Onmund is not following you. You can also use console click on her, type disable then type enable to see if the options change. and another way I fix it is well there was a mod I had installed that I didn't realize causes issues. The mod " To your face" or any mod that changes when an NPC talks to you can cause issues with shez. There are dialogs that need to trigger without interruption, and mods like To your face, interrupt the flow of some dialogs thus causing Onmund of ingv to not be responsive or to have missing dialog trees. So check your load order for any mods that may do these type of things. This is what helped me but if none of this helps, my apologies. Hope all the best. The problem is solved by removing https://www.nexusmods.com/skyrim/mods/86872 / https://www.nexusmods.com/skyrim/mods/92811 Kaidan :( Looks like Onmund and Kaidan just cannot get along XDDDDD