ok here is the situation. I have a son (not heir) who I want to marry a duchess and the betrothal was accepted. I dont get an icon at the top of the screen but I am getting proposals from her to MATRILINEALLY marry. that was not the deal. What do I do to get the marriage done from my end or at least see if she is still willing to do it. Am I doomed to just wait on the AI to send me the correct message?
It's pretty normal for them to try to suggest to marry the other way around once they come of age, but you don't have to do that. You should still have the popup saying "betrothed can marry" at the top of the screen, but it's possible that you disabled the alert. To re-enable the alert, to go the outliner on the right hand side of the screen, click the button that says "open outliner category information" (it's just above where it lists your holdings) and then check "disabled alerts". Your disabled alerts will now appear in the outliner and you can click to reenable them.
It's also sometimes the case that the AI will change its mind about the betrothal later on and not accept, possibly because their child got much better stats, or moved up in the line of inheritance.